Ultra cheep violet laser diode!
leslie...@hotmail.com
its been a long time since I posted here, but this may be
of some interest!
I recently purchased, for the princely sum of around £40 UKP, a
replacement Laser reader assembly, for a Sony Playstation-3, With the
sole interest of extracting the Violet Laser diode.
The Assembly arrived this morning, and I stripped it to bits this
afternoon. I have worked out the pinouts of the diode (they are
somewhat strange!) and now have a working violet laser !!!!
I have taken photos at each stage of disassemby, and I will be
uploading to a website and posting the URL here later on tonight
(probably late, around 2am)
The Laser diode unit contains TWO laser diodes! one is red, the other
violet (hence the wierd pin-out!)
When the site is up, Sam is more than welcome to use the description
and photos for the LaserFAQ!
rgds
Leslie Wright
Dr Bob
I cant wait to see your pics
where did you buy the pickup assy from?
Rob
<leslie...@hotmail.com> wrote in message
news:1173380531.7...@h3g2000cwc.googlegroups.com...
Hello all,
its been a long time since I posted here, but this may be
of some interest!
I recently purchased, for the princely sum of around Ł40 UKP, a
martijn
"Dr Bob" <sta...@hotmail.com> wrote in message
news:45f06c36$0$8735$ed26...@ptn-nntp-reader02.plus.net...
> Hi Leslie
> I cant wait to see your pics
> where did you buy the pickup assy from?
>
> Rob
>
>
> <leslie...@hotmail.com> wrote in message
> news:1173380531.7...@h3g2000cwc.googlegroups.com...
> Hello all,
> its been a long time since I posted here, but this may be
> of some interest!
>
> I recently purchased, for the princely sum of around £40 UKP, a
Dr Bob
they are already there like the man says for around £40 plus shipping
i think i will order one for some blue fun
Rob
"martijn" <mv...@chello.nl> wrote in message
news:17e16$45f07479$3ec247f8$11...@news.chello.nl...
martijn
need me a blue laser pointer ;)
already have homebuild green 50 mw red 100 mw
so would be cool to build a blue one
wickeds are nice but way to expensive for the power
and its more fun to build yourself ;)
"Dr Bob" <sta...@hotmail.com> wrote in message
news:45f076a7$0$8719$ed26...@ptn-nntp-reader02.plus.net...
leslie...@hotmail.com
apologies for the apalling spelling of the word
"cheep" I keep doing that!
Anyway, I have put up a web page detailing the dissection of the PS3
laser is is:
http://www.fineartradiography.com/hobbies/lasers/blu-ray/index.html
any feedback would be greatly appreciated!
leslie...@hotmail.com
martijn
take a look guys looks very good
http://www.fineartradiography.com:80/hobbies/lasers/blu-ray/index.html
"martijn" <mv...@chello.nl> wrote in message
news:4ca2a$45f07d8d$3ec247f8$15...@news.chello.nl...
leslie...@hotmail.com
Dr Bob
Gotta get me one of those!
pictures are cool well done on a great find. I still cant beleive they are so cheap! or should that be cheep :)
Rob
Sam Goldwasser
> Hello again!
> apologies for the apalling spelling of the word
> "cheep" I keep doing that!
>
> Anyway, I have put up a web page detailing the dissection of the PS3
> laser is is:
>
> http://www.fineartradiography.com/hobbies/lasers/blu-ray/index.html
This is really cool. :) And the fact that they can mfg. a violet laser
diode, two cube beamsplitters, those other lenses and adjustable lens, so
inexpensively is truly amazing.
How stable is your Web site? I'd much rather simply link to it.
> any feedback would be greatly appreciated!
Maybe reshoot the detailed view so it's in focus. ;-)
Thanks and thanks for your efforts!
--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
Lostgallifreyan
news:1173389230.1...@j27g2000cwj.googlegroups.com:
Nice. Someone on a forum raised the possibility of a hoax, but it looks
entirely real to me, it's just the price that's astonishing. I bought one.
With odds like these, a presbyterian would turn into a betting man. >:)
leslie...@hotmail.com
glad you like it, I will re-shoot the innards tomorrow.
I`m not so sure that these things are manufactured as inexpensively,
as we are lead to believe! Im under the distinct impression that SONY
are prepared to make high losses initially to get the technology
out! :)
You realy have got to see the insides of one of these things for
yourself! It truly is a thing of beauty! I`ve taken apart many CD
drive assemblies, only to find that all the optics excluding the
mirror are made of plastic! This stuff is real glass! ;-) Theres
probably an holographic optical element in there some where, but I
will wait until after I`ve re-photographed it again.
The website is stable, as my x-ray art site is hosted on it . So by
all means link to it :)
rgds
Les
leslie...@hotmail.com
I was originaly going to buy an x-box360 HD-DVD drive, which are
currently listed at £115 ! until I thought of searching for
replacement drive carriages!
Lostgallifreyan
news:1173402411....@j27g2000cwj.googlegroups.com:
I bought one. I also consider looking for spares as a way to go, but I had
no idea they'd already show, let alone cheap, so I never looked. Good call.
leslie...@hotmail.com
Its definately worth it!
by the way on which forum was it suggested that this may be a hoax?
Lostgallifreyan
news:1173403924....@8g2000cwh.googlegroups.com:
> On 9 Mar, 01:19, Lostgallifreyan <no-...@nowhere.net> wrote:
>> lesliewrig...@hotmail.com wrote
>> innews:1173402411.760344.57600@j27g2000cw
> j.googlegroups.com:
>>
>> > Its VERY real! £40 UKP on e-bay!
>>
>> > I was originaly going to buy an x-box360 HD-DVD drive, which are
>> > currently listed at £115 ! until I thought of searching for
>> > replacement drive carriages!
>>
>> I bought one. I also consider looking for spares as a way to go, but
>> I had no idea they'd already show, let alone cheap, so I never
>> looked. Good cal
> l.
>
>
> Its definately worth it!
>
> by the way on which forum was it suggested that this may be a hoax?
>
>
Photonlexicon. (URL won't be conveniently clickable..)
http://www.photonlexicon.com/forums/showthread.php?s=2c917eb222ed1700b6f234
b9316a279c&t=2177&page=2
Wasn't a serious assertion though, just one guy expressed the thought that
if it looked too good to be true, it probably is. The word hoax didn't
arise till another guy said it wasn't one. No-one else has any problem with
the observation, and at least two people have bought a spare widget on the
strength of this. I suspect your site viewing figures might rocket for a
while too. Nice x-rays, btw, I really like the tiny electronics ones, and
the sea shells.
leslie...@hotmail.com
> lesliewrig...@hotmail.com wrote innews:1173403924....@8g2000cwh.googlegroups.com:
>
>
>
> > On 9 Mar, 01:19, Lostgallifreyan <no-...@nowhere.net> wrote:
> >> lesliewrig...@hotmail.com wrote
> >> innews:1173402411.760344.57600@j27g2000cw
> > j.googlegroups.com:
>
> >> > Its VERY real! £40 UKP on e-bay!
>
> >> > I was originaly going to buy an x-box360 HD-DVD drive, which are
> >> > currently listed at £115 ! until I thought of searching for
> >> > replacement drive carriages!
>
> >> I bought one. I also consider looking for spares as a way to go, but
> >> I had no idea they'd already show, let alone cheap, so I never
> >> looked. Good cal
> > l.
>
> > Its definately worth it!
>
> > by the way on which forum was it suggested that this may be a hoax?
>
> b9316a279c&t=2177&page=2
>
> Wasn't a serious assertion though, just one guy expressed the thought that
> if it looked too good to be true, it probably is. The word hoax didn't
> arise till another guy said it wasn't one. No-one else has any problem with
> the observation, and at least two people have bought a spare widget on the
> strength of this. I suspect your site viewing figures might rocket for a
> while too. Nice x-rays, btw, I really like the tiny electronics ones, and
> the sea shells.
LOL I thought that same thought, when I saw the assembly on the bay!
I'm just afraid that when the guy cottons on, he will up his prices!
I can see this little episode propagating across the net like
wildfire!
Glad you liked the x-rays! Im hoping that it will become one of those
hobbies that pays for itself!
Let me know how you get on when your unit arrives :)
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173402411....@j27g2000cwj.googlegroups.com...
I can not find any on ebay...can someone post a link? Thanx
leslie...@hotmail.com
Hi ,
just do a search for PS3 laser or KES-400AAA , (search
worldwide).
The guy had around 500 left , last time I looked!.
rgds
Leslie
Sam Goldwasser
> Hi Sam,
> glad you like it, I will re-shoot the innards tomorrow.
> I`m not so sure that these things are manufactured as inexpensively,
> as we are lead to believe! Im under the distinct impression that SONY
> are prepared to make high losses initially to get the technology
> out! :)
Yes, but they don't have to accept high losses on repair parts! A typical
automobile would cost 10X or 20X the selling price if built from service
parts!
> You realy have got to see the insides of one of these things for
> yourself! It truly is a thing of beauty! I`ve taken apart many CD
> drive assemblies, only to find that all the optics excluding the
> mirror are made of plastic! This stuff is real glass! ;-) Theres
> probably an holographic optical element in there some where, but I
> will wait until after I`ve re-photographed it again.
Yes, I'd really love to. I'm not sure I'm ready to pay yet though. :)
> The website is stable, as my x-ray art site is hosted on it . So by
> all means link to it :)
Great, so it shall be!
Thanks.
Sam Goldwasser
> Tom Cue wrote:
> > <leslie...@hotmail.com> wrote in message
> > news:1173402411....@j27g2000cwj.googlegroups.com...
> > Its VERY real! =A340 UKP on e-bay!
> >
> > I was originaly going to buy an x-box360 HD-DVD drive, which are
> > currently listed at =A3115 ! until I thought of searching for
> > replacement drive carriages!
> >
> >
> >
> > I can not find any on ebay...can someone post a link? Thanx
>
> Hi ,
> just do a search for PS3 laser or KES-400AAA , (search
> worldwide).
> The guy had around 500 left , last time I looked!.
I wonder which truck they fell off of? :)
leslie...@hotmail.com
> lesliewrig...@hotmail.com writes:
> > Tom Cue wrote:
> > > <lesliewrig...@hotmail.com> wrote in message
Hi Sam,
I wonder too! ;-)
As per you previous request, I have uploaded a much clearer pictue of
the optics. Its so clear I didnt even bother marking out the beam-
path, because its so obvious!
rgds
Leslie
martijn
"Dr Bob" <sta...@hotmail.com> wrote in message news:45f08fac$0$8716$ed26...@ptn-nntp-reader02.plus.net...
LesioQ
problems.
http://www.eetimes.com/showArticle.jhtml?articleID=194400941
My biggest concern is it's lifetime, as it's manufacturing process is
not as mature as for red/IR region LDs.
Piotr.K
leslie...@hotmail.com
Hi,
The lifetime quoted in the article, is 10,000 hours, which is more
than enough for my uses ;)
Sam Goldwasser
be interested in the rest of it. Let me know how much you would want.
Pleae contact me via the Feedback form at www.repairfaq.org if you don't
have my email address.
Sam Goldwasser
> On 9 Mar, 13:13, Sam Goldwasser <s...@blue.seas.upenn.edu> wrote:
> > lesliewrig...@hotmail.com writes:
> > > Tom Cue wrote:
> > > > <lesliewrig...@hotmail.com> wrote in message
> > > >news:1173402411....@j27g2000cwj.googlegroups.com...
> > > > Its VERY real! =A340 UKP on e-bay!
> >
> > > > I was originaly going to buy an x-box360 HD-DVD drive, which are
> > > > currently listed at =A3115 ! until I thought of searching for
> > > > replacement drive carriages!
> >
> > > > I can not find any on ebay...can someone post a link? Thanx
> >
> > > Hi ,
> > > just do a search for PS3 laser or KES-400AAA , (search
> > > worldwide).
> > > The guy had around 500 left , last time I looked!.
> >
> > I wonder which truck they fell off of? :)
> >
> > --- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
> Hi Sam,
> I wonder too! ;-)
> As per you previous request, I have uploaded a much clearer pictue of
> the optics. Its so clear I didnt even bother marking out the beam-
> path, because its so obvious!
Great!
BTW, there's something strange about the font colors on the index page
(or how my system is set up). I have to go in and change all the
instances of (255, 255, 255) to (0,0,0) for the text to show up *after*
I save it.)
leslie...@hotmail.com
Hi,
yes, the font colour is white, to contrast with the background
image. I had it that way, so it would be in keeping with the theme of
the x-ray site.
I hadnt realy given that a lot of thought when I designed the site.
ooooops!
rgds
Leslie
leslie...@hotmail.com
Hi again,
I just fixed it :)
Jürgen Appel
> http://www.fineartradiography.com/hobbies/lasers/blu-ray/index.html
> any feedback would be greatly appreciated!
Nice documentation.
Are your beam splitter cubes polarizing beam splitters?
I'd expect the bigger one to be a PBS, maybe just for one color.
I would also guess that your window 'M' is a quarter wave plate, so that
backreflected light changes its polarization and gets reflected into the
direction of the photodiodes.
Greetings,
Jürgen
--
GPG key:
http://pgp.mit.edu:11371/pks/lookup?search=J%FCrgen+Appel&op=get
Adam Aglionby
> Hello all,
> its been a long time since I posted here, but this may be
> of some interest!
>
> I recently purchased, for the princely sum of around £40 UKP, a
> replacement Laser reader assembly, for a Sony Playstation-3, With the
> sole interest of extracting the Violet Laser diode.
>
> The Assembly arrived this morning, and I stripped it to bits this
> afternoon. I have worked out the pinouts of the diode (they are
> somewhat strange!) and now have a working violet laser !!!!
>
> I have taken photos at each stage of disassemby, and I will be
> uploading to a website and posting the URL here later on tonight
> (probably late, around 2am)
>
> The Laser diode unit contains TWO laser diodes! one is red, the other
> violet (hence the wierd pin-out!)
>
> When the site is up, Sam is more than welcome to use the description
> and photos for the LaserFAQ!
>
> rgds
> Leslie Wright
So its possible to have RG&B lasers for sub 200 USD now , wow!
As the can has both a red and blue laser just need a very compact
trichro and theoretically possible to get the Holy grail, a white
light laser pointer :-)
Adam
leslie...@hotmail.com
> lesliewrig...@hotmail.com schrieb:
I would imagine that the beamsplitters are polarizing splitters, I
will test them this evening, and add the findings to my site.
Thanks
Leslie :)
leslie...@hotmail.com
Hi,
that would be nice! The problem is the ratios of colours. The red
diode in the can appears to put out maybe 1 or 2 mW at most, whereas
the violet diode appeas to put out somewhere in the region of 10-20
mW.
I suppose could could under-run the violet diode, but where is the
fun in that!
Mixing violet, and 10mW red gives "a very strange and beautiful
colour" (according to my Mum)(Its a shame I will never see it, I am
red-green colour-blind , so it just looks violet/white to me).
The diode can is only 5.6mm dia, so I suppose you could mount Red,
and Violet side by side, and introduce your green somehow. Maybe with
a good eye and a steady hand, you could assemble an RGB pointer,
complete with miniature trichro, that would have an O/D of maybe 12mm?
Would be very cool though!
:)
James Sweet
>
>
> So its possible to have RG&B lasers for sub 200 USD now , wow!
> As the can has both a red and blue laser just need a very compact
> trichro and theoretically possible to get the Holy grail, a white
> light laser pointer :-)
>
>
Anybody tried mixing this "blue" with other colors to see how it does?
It's more of a dim violet so I'm not sure how good of an RGB mix you'd get.
leslie...@hotmail.com
Hi,
yes I tried it this afternoon. I mixed it with 5mW of red@650nm and
8mW of green@532nm.
It appears blue-white, or "ice-white". I don`t know the output of this
thing yet, I`m guessing 10-20mW, as this is in keeping with what I`ve
seen, and the various datasheets I`ve read.
I have posted a new image on my site, of red, green and violet next
to each other for comparison, to give an Idea of relative brightness.
Rgds
Leslie
Mike Harrison
I wonder if there might be thermal issues running the violet and red at the same time, as they are
not designed to do this in normal usage.
Sam Goldwasser
I'm also suspect of his guess at 15 or 20 mW. There would be no need for
anything above 1 or 2 mW, similar to red, for reading.
405 nm is just barely visible as a really deep purple, nothing like what
the photos show on Leslie's Web page. Usually, it shows up mostly as
fluorescence where it hits. Perhaps it's a longer wavelength. Anyone
have a monochromator to check?
leslie...@hotmail.com
Hi Sam,
yes it does seem a bizarrely high output power. However if
the literature is to believed, then it is a 405nm diode. The diode
extracted from a blu-ray DVD player by wickedlasers was found to
output around 20mW too.
Do you have any idea about the reliability or linearity of the
monitor photocell in the JDSU Argon ion heads?
I stripped one out of an old head today, and took the following
measurements, first of my argon at 488nm, then a single measurement of
the violet diode.
Argon output according | Meter output mV
to psu display
5.3mW 348mV
8mW 368mV
10mW 376mV
11mW 381mV
12mW 385mV
etc...
18mW 403mV
19mW 406mV
20mW 408mV
Violet Diode = 425mV
I know violet should have a higher work function that 488nm blue, but
if is was only a milliwatt or two, I wouldnt have expected it to be
this much?
Leslie
leslie...@hotmail.com
Hi again!
just measured it with 2 1meter rulers, and a 1000 lines/
mm diffraction grating, I get 403-406nm.
The apparatus was calibrated with doubled yag at 532nm an He-Ne at
632.8nm.
rgds
Leslie
heruursciences
probably more, since GaN has a high damage threashold and very high
gain, but at that power, it will mode hop, cycle, and fluxuate over a
wide range of modes and power. What few nitride based LD's i've come
across were exceptionally noisy optically when run much above the
threashold; if they were not feedback monitored and thermally
stabalized then the modehops and noise are absolutely dreadful. This
is largely irrelevent if all you need is a purple dot, but if trying
for hollography forget it. My best guess is they likely run them as at
a couple milawatts in a stable region in the operating range.
leslie...@hotmail.com
That makes a lot of sense, given what I have seen. I`m just in the
middle of plotting a graph of voltage versus light output, and it is
unlike any graph for a laser diode I have ever seen. The light output
increases dramatically to begin with. Then, when it thresholds, the
slope levels off somewhat. The fragments of data I have regarding the
Nichia laser diodes, quote 3 slope efficiencies(for the same diode) ,
dependent on drive current. This may explain the odd curve.
I will be posting the new graph (in place of the old one) tonight.
Thanks for the info!
Rgds
Leslie
Lostgallifreyan
news:1173639734.2...@8g2000cwh.googlegroups.com:
> I believe they are most likely capable of running at say 20mw,
> probably more
Snip..
> My best guess is they likely run them as at
> a couple milawatts in a stable region in the operating range.
>
Mine too, given that this is a sensitive product launch on a huge scale, so
the makers might use more powerful diodes to make sure they can run them
very safely at the needed power, to avoid problems. They overengineered the
other optics, so I'm sure they didn't scrimp on the diode.
Sam Goldwasser
> On 11 Mar, 12:21, Sam Goldwasser <s...@blue.seas.upenn.edu> wrote:
> > James Sweet <jamessw...@hotmail.com> writes:
> > > > So its possible to have RG&B lasers for sub 200 USD now , wow!
> > > > As the can has both a red and blue laser just need a very compact
> > > > trichro and theoretically possible to get the Holy grail, a white
> > > > light laser pointer :-)
> >
> > > Anybody tried mixing this "blue" with other colors to see how it does?
> > > It's more of a dim violet so I'm not sure how good of an RGB mix you'd get.
> >
> > I'm also suspect of his guess at 15 or 20 mW. There would be no need for
> > anything above 1 or 2 mW, similar to red, for reading.
> >
> > 405 nm is just barely visible as a really deep purple, nothing like what
> > the photos show on Leslie's Web page. Usually, it shows up mostly as
> > fluorescence where it hits. Perhaps it's a longer wavelength. Anyone
> > have a monochromator to check?
> >
> > --- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
> Hi Sam,
> yes it does seem a bizarrely high output power. However if
> the literature is to believed, then it is a 405nm diode. The diode
> extracted from a blu-ray DVD player by wickedlasers was found to
> output around 20mW too.
>
> Do you have any idea about the reliability or linearity of the
> monitor photocell in the JDSU Argon ion heads?
>
> I stripped one out of an old head today, and took the following
> measurements, first of my argon at 488nm, then a single measurement of
> the violet diode.
>
> Argon output according | Meter output mV
> to psu display
>
> 5.3mW 348mV
> 8mW 368mV
> 10mW 376mV
> 11mW 381mV
> 12mW 385mV
> etc...
> 18mW 403mV
> 19mW 406mV
> 20mW 408mV
>
> Violet Diode = 425mV
If that's true, it might be a lot higher than 20 mW. The sensitivity
of the PD declines sharply toward violet.
But do another test: Measure the current from the PD, preferably if reverse
biased with a few V. That will be more accurate.
> I know violet should have a higher work function that 488nm blue, but
> if is was only a milliwatt or two, I wouldnt have expected it to be
> this much?
It's actually backwards as noted above. Measure the current and report
back. :)
leslie...@hotmail.com
Ok, I will measure again tomorrow, and post my findings.
Out of interest the PlayStation 3 optical pickup ( KES-400AAA) is also
available from:
http://www.laserlens.cn/ The price is rumored to be around £30 UKP
(according to photonlexicon forums)
:-)
Andy Cuffe
s.
>
>Ok, I will measure again tomorrow, and post my findings.
>
>
>Out of interest the PlayStation 3 optical pickup ( KES-400AAA) is also
>available from:
>
>http://www.laserlens.cn/ The price is rumored to be around £30 UKP
>(according to photonlexicon forums)
>
>:-)
I'm curious what Sony is charging for them. Do you know the Sony part
number? It will be a 9 digit number with dashes and should be on the
box (something like 8-820-005-02).
Andy Cuffe
leslie...@hotmail.com
Hi,
I retested today, with the Photocell reverse biased:
Argon ion @488nm | Meter output mA
10mW 0.110mA
15mW 0.169mA
20mW 0.229mA
25mW 0.285mA
Violet diode 0.211mA @ 39mA drive
current
0.379mA @ 50mA drive
current
rgds,
Leslie
leslie...@hotmail.com
Hi,
I`m afraid not as the unit did not arrive in a box, just an
antistatic bag.
There are several labels on the product, and they are as follows:
Label #1 on the pickup:
KES-400A
1207
060822
0055
+ 2D barcode
Label #2 on the pickup base:
120706
08220055
23860207
R-10T+06 B
+2D barcode
Label #3 on chassis
KEM-400AAA
23860207B
+2D barcode
Sam Goldwasser
> Hi,
> I retested today, with the Photocell reverse biased:
>
>
> Argon ion @488nm | Meter output mA
>
> 10mW 0.110mA
> 15mW 0.169mA
> 20mW 0.229mA
> 25mW 0.285mA
>
> Violet diode 0.211mA @ 39mA drive
> current
> 0.379mA @ 50mA drive
> current
>
> rgds,
> Leslie
Geez, you may be looking at more than 50 mW if the PD response is
anything like:
http://www.repairfaq.org/sam/sipdresp.gif
leslie...@hotmail.com
WOW! , that sounds a little high though.
I drew a black spot on my wrist, and put it in the beam to see if I
could sense it, but no. I focussed it do a small point, and I can feel
it then.
I will test again, tomorrow, in case I have made an error, but I had
taken multiple measurements of each Laser with the same cell under the
same conditions. The only difference that springs to mind is beam
diameter. The argon is about 0.74mm and the Violet Laser diode is 5mm.
Sam Goldwasser
> On 12 Mar, 23:06, Sam Goldwasser <s...@red.seas.upenn.edu> wrote:
> > lesliewrig...@hotmail.com writes:
> > > Hi,
> > > I retested today, with the Photocell reverse biased:
> >
> > > Argon ion @488nm | Meter output mA
> >
> > > 10mW 0.110mA
> > > 15mW 0.169mA
> > > 20mW 0.229mA
> > > 25mW 0.285mA
> >
> > > Violet diode 0.211mA @ 39mA drive
> > > current
> > > 0.379mA @ 50mA drive
> > > current
> >
> > > rgds,
> > > Leslie
> >
> > Geez, you may be looking at more than 50 mW if the PD response is
> > anything like:
> >
> > http://www.repairfaq.org/sam/sipdresp.gif
> >
> > --- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
> WOW! , that sounds a little high though.
>
> I drew a black spot on my wrist, and put it in the beam to see if I
> could sense it, but no. I focussed it do a small point, and I can feel
> it then.
>
> I will test again, tomorrow, in case I have made an error, but I had
> taken multiple measurements of each Laser with the same cell under the
> same conditions. The only difference that springs to mind is beam
> diameter. The argon is about 0.74mm and the Violet Laser diode is 5mm.
The PD shouldn't be that sensitive to the beam area if it is reverse
biased but try reducing the spot size and see if it makes a major
difference.
leslie...@hotmail.com
Whilst experimenting with the diode, last night, I noticed that the
output appeared somewhat unstable. (the output was noisy, ie
flickering somewhat)
Today, when I was looking at the spot It seemed somewhat dimmer than
it was yesterday. Upon expanding the spot, almost half of the spot is
at least 50% dimmer, than the rest of the spot! (the thing DOES still
lase)
I can only conclude therefore that the Laser diode was damaged, in
yesterdays tests (it was pushed to 52mA).
This pushes the reasonable range of operation to around 30-40mA. I
strongly suspect COD as the cause, as no heating of the Laser diode
can was detected.
Fortunately, I had ordered another unit last week, so it should be
with me soon!
At least we now all know the upper limit! ;-)
This of course brings into question the validity of the last series of
tests. I will perform a new set of tests, when the new unit arrives.
I will be posting a picture of the spot from the damaged unit on the
website tonight.
Leslie
Lostgallifreyan
news:1173799917....@h3g2000cwc.googlegroups.com:
> This of course brings into question the validity of the last series of
> tests. I will perform a new set of tests, when the new unit arrives.
>
> I will be posting a picture of the spot from the damaged unit on the
> website tonight.
>
They're ALL valid. Hindsight doesn't invalidate them, this is new ground...
Also, there is a further test you can make with the old one, if parts of it
are lasing at original power. Retroreflection. Try shining its light back
at it with an ordinary domestic mirror and see if that kills it. I'd not
have suggested this test for a new diode, though it's important to find out
if these diodes are at risk, but in this case you seem to have an ideal
situation for making that test.
leslie...@hotmail.com
Ah yes, I've heard of this problem with high power visible diodes.
Ok I tested the diode this morning, as I said it still lases
(although, at at half intensity maybe less):
The diode was powered at about 40ma, with its collimating lens in
place. A first surface mirror was used to direct the beam back into
the device. No further damage to the laser diode was observed, however
I noted during the test that when the beam is directed back into the
Laser diode, the laser scatter from the optics reduces somewhat
(suggesting that is is killing lasing, if only transiently).
Having said this, I still would not recommend this for a new laser
diode. (the above test can not be definitive given its reduced output)
However, it would seem that they are not as susceptible as higher
powered devices. I certainly wont be worrying about the 5% or so
reflected back, from non AR coated optics.
Leslie
Lostgallifreyan
news:1173870371.9...@l75g2000hse.googlegroups.com:
Thanks for that. It's info I think is important. It's always unsettling, to
know that a diode laser can be so easily and instantly destroyed by an
event so far from it, no matter what electrical and physical protections
are in place.
I remember that the non-destructive disturbance to lasing could be caused
in 35 mW Opnext diodes. While a part-dead blue might not show much, you
said some regions were at full output rather than the whole being reduced,
so I guess if there is no permanent change in the remaining intense areas,
it migth be that they can stand retroreflection when intact, too. I won't
be in a hurry to try that though. My first move might be to get mine into a
module and sold ASAP, to fund buying more, as that way I can afford to be
more reckless. I usually test to destruction before testing, but in this
case I'll just run at safe values and watch it run for a while first.
leslie...@hotmail.com
> lesliewrig...@hotmail.com wrote innews:1173870371.9...@l75g2000hse.googlegroups.com:
>
>
>
> > On 14 Mar, 02:49, Lostgallifreyan <no-...@nowhere.net> wrote:
> >> lesliewrig...@hotmail.com wrote
> >> innews:1173799917....@h3g2000cwc.googlegroups.com:
>
> >> > This of course brings into question the validity of the last series
> >> > of tests. I will perform a new set of tests, when the new unit
> >> > arrives.
>
> >> > I will be posting a picture of the spot from the damaged unit on
> >> > the website tonight.
>
> >> They're ALL valid. Hindsight doesn't invalidate them, this is new
> >> ground...
>
> >> Also, there is a further test you can make with the old one, if parts
> >> of it are lasing at original power. Retroreflection. Try shining its
> >> light back at it with an ordinary domestic mirror and see if that
> >> kills it. I'd not have suggested this test for a new diode, though
> >> it's important to find out if these diodes are at risk, but in this
> >> case you seem to have an ideal situation for making that test.
>
> > Ah yes, I've heard of this problem with high power visible diodes.
>
> > Ok I tested the diode this morning, as I said it still lases
> > (although, at at half intensity maybe less):
>
> > The diode was powered at about 40ma, with its collimating lens in
> > place. A first surface mirror was used to direct the beam back into
> > I noted during the test that when the beam is directed back into the
> > (suggesting that is is killing lasing, if only transiently).
> > Having said this, I still would not recommend this for a newlaser
> > diode. (the above test can not be definitive given its reduced output)
> > However, it would seem that they are not as susceptible as higher
> > powered devices. I certainly wont be worrying about the 5% or so
> > reflected back, from non AR coated optics.
>
> > Leslie
>
> Thanks for that. It's info I think is important. It's always unsettling, to
> event so far from it, no matter what electrical and physical protections
> are in place.
>
> I remember that the non-destructive disturbance to lasing could be caused
> in 35 mW Opnext diodes. While a part-dead blue might not show much, you
> said some regions were at full output rather than the whole being reduced,
> so I guess if there is no permanent change in the remaining intense areas,
> it migth be that they can stand retroreflection when intact, too. I won't
> be in a hurry to try that though. My first move might be to get mine into a
> module and sold ASAP, to fund buying more, as that way I can afford to be
> more reckless. I usually test to destruction before testing, but in this
> case I'll just run at safe values and watch it run for a while first.
I was thinking along the same lines. I had e-mailed roithner lasers in
Austria this morning, for a quote for some driver IC's, the have the
common cathode case drivers, and IC's, plus collimating optics etc.
In the meantime, I'm sticking with current regulators, whilst I modify
a driver I saw on Sam's LaserFAQ.
Leslie
leslie...@hotmail.com
>
> Thanks for that. It's info I think is important. It's always unsettling, to
> know that a diode laser can be so easily and instantly destroyed by an
> event so far from it, no matter what electrical and physical protections
> are in place.
>
> I remember that the non-destructive disturbance to lasing could be caused
> in 35 mW Opnext diodes. While a part-dead blue might not show much, you
> said some regions were at full output rather than the whole being reduced,
> so I guess if there is no permanent change in the remaining intense areas,
> it migth be that they can stand retroreflection when intact, too. I won't
> be in a hurry to try that though. My first move might be to get mine into a
> module and sold ASAP, to fund buying more, as that way I can afford to be
> more reckless. I usually test to destruction before testing, but in this
> case I'll just run at safe values and watch it run for a while first.
When anyone gets their Violet Laser diodes up and running, could
someone please measure the optical output, at say threshold, 30ma 33mA
and 36mA?
That way I can post more complete data for everyone at the site.
I dont expect anyone to test their diodes to destruction, so I will
extrapolate the rest, based on my measurements and yours.
Many thanks
Leslie
Dr Bob
post the results as soon as I can
Rob
<leslie...@hotmail.com> wrote in message
news:1173886198.4...@o5g2000hsb.googlegroups.com...
Lostgallifreyan
nntp-reader02.plus.net:
> I have one on the way and have a lasercheck so will perform the tests and
> post the results as soon as I can
>
Likewise. I'll also try to get a reading off my DIY thermopile meter. It
will be calibrated from a Lasercheck though, but should remove uncertainty
of wavelength, if any. The main problem with that would sensitivity, but
I'll have a go anyway.
leslie...@hotmail.com
> "Dr Bob" <stan...@hotmail.com> wrote innews:45f81f7c$0$8719$ed2619ec@ptn-
Thanks guys that would be great! ;-)
I turned my broken diode into a pointer today, just for fun, though I
cant wait for my new diode to arrive.
Leslie
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173890495.8...@n59g2000hsh.googlegroups.com...
I've ordere my unit to. Unfortunatley, i don't have any equipment to mesure
optical output..but can you send me schematics that you have used for
pointer?
leslie...@hotmail.com
> <lesliewrig...@hotmail.com> wrote in message
Hi,
for the pointer I just used a 4AAA batteries and 47ohm resistor in
series with the diode (the pinout is on the web site). I wouldn't
recommend running laser diodes in this manner, (although this is
exactly how most 1.99 pointers are made) a proper drive circuit needs
to be designed.
My particular diode was damaged during tests, so I'm not especially
bothered if it dies now.
rgds
Leslie
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173896418.9...@o5g2000hsb.googlegroups.com...
Yeah, i've read about that diode...ok, if u know some circuit that i could
use, please let me know. I'm from croatia btw so i don't have any shop in my
country where i can buy hobbist stuff specialized for laser(like drivers) so
probobly i need to order some just don't know where from...
leslie...@hotmail.com
http://www.roithner-laser.com/Drivers.htm sells ready made drivers,
its the CCC laser driver board, they arent expensive, but I have not
tried one with this Laser Diode.
I will be trying a current regulator, such as the LM317 for pointers,
there are just three legs on the device, volts-in, volts-out, and
volts-set.
For a lab device, you will be wanting optical feedback control (+ your
diode will live longer!), so go with roithner.
rgds
Leslie
leslie...@hotmail.com
> > > exactly how most 1.99 pointers are made) a proper drive circuit needs
> > > to be designed.
> > > My particular diode was damaged during tests, so I'm not especially
> > > bothered if it dies now.
>
> > > rgds
> > > Leslie
>
> > Yeah, i've read about that diode...ok, if u know some circuit that i could
> > use, please let me know. I'm from croatia btw so i don't have any shop in my
> > probobly i need to order some just don't know where from...
>
> its the CCClaserdriver board, they arent expensive, but I have not
> tried one with thisLaserDiode.
>
> I will be trying a current regulator, such as the LM317 for pointers,
> there are just three legs on the device, volts-in, volts-out, and
> volts-set.
>
> For a lab device, you will be wanting optical feedback control (+ your
> diode will live longer!), so go with roithner.
>
> rgds
> Leslie
OR if you already have an e-bay account, take a look at this:
http://cgi.ebay.co.uk/LASER-DIODE-LED-DRIVER-150mA-constant-current-source_W0QQitemZ120097284287QQcategoryZ109452QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
according to the listing, you can run it WITHOUT photodiode feedback
(remember, on the PS3 diode all cathodes are common, so you wont be
able to use your photodiode, with a common supply such as this), but
if you are just after a violet beam, without the trimmings, then this
may do the job.
rgds
Leslie
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173902559....@d57g2000hsg.googlegroups.com...
Thanx a LOT for help...i don't think i'm gonna use it as a lab device, just
would like to make a pointer. I have massive chrome case i've made for green
pointer to keep it more cool but i have 2 of them so i've been thinking to
use it for this blue even if i don't want to push it over limit to make
diode warm...
leslie...@hotmail.com
> >> > exactly how most 1.99 pointers are made) a proper drive circuit needs
> >> > to be designed.
> >> > My particular diode was damaged during tests, so I'm not especially
> >> > bothered if it dies now.
>
> >> > rgds
> >> > Leslie
>
> >> Yeah, i've read about that diode...ok, if u know some circuit that i
> >> could
> >> use, please let me know. I'm from croatia btw so i don't have any shop in
> >> my
> >> so
> >> probobly i need to order some just don't know where from...
>
> > its the CCClaserdriver board, they arent expensive, but I have not
> > tried one with thisLaserDiode.
>
> > I will be trying a current regulator, such as the LM317 for pointers,
> > there are just three legs on the device, volts-in, volts-out, and
> > volts-set.
>
> > For a lab device, you will be wanting optical feedback control (+ your
> > diode will live longer!), so go with roithner.
>
> > rgds
> > Leslie
>
> Thanx a LOT for help...i don't think i'm gonna use it as a lab device, just
> would like to make a pointer. I have massive chrome case i've made for green
> pointer to keep it more cool but i have 2 of them so i've been thinking to
> use it for this blue even if i don't want to push it over limit to make
> diode warm...
The diode doesn't get particularly warm during operation, although a
small heatsink would be advisable. Don't make the diode too cool
though, as this will drop the threshold current , and as its not going
to be light feedback regulated, this could conceivably destroy the
diode through COD (Catastrophic Optical Damage).
Leslie
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173910432.1...@e65g2000hsc.googlegroups.com...
leslie...@hotmail.com
> >> > its the CCClaserdriver board, they arent expensive, but I have not
> >> > tried one with thisLaserDiode.
>
> >> > I will be trying a current regulator, such as the LM317 for pointers,
> >> > there are just three legs on the device, volts-in, volts-out, and
> >> > volts-set.
>
> >> > For a lab device, you will be wanting optical feedback control (+ your
> >> > diode will live longer!), so go with roithner.
>
> >> > rgds
> >> > Leslie
>
> >> Thanx a LOT for help...i don't think i'm gonna use it as a lab device,
> >> just
> >> would like to make a pointer. I have massive chrome case i've made for
> >> green
> >> pointer to keep it more cool but i have 2 of them so i've been thinking
> >> to
> >> use it for this blue even if i don't want to push it over limit to make
> >> diode warm...
>
> > The diode doesn't get particularly warm during operation, although a
> > small heatsink would be advisable. Don't make the diode too cool
> > though, as this will drop the threshold current , and as its not going
> > to be light feedback regulated, this could conceivably destroy the
> > diode through COD (Catastrophic Optical Damage).
>
> > Leslie
>
> How else should prevent COD?? AR lens?
No, I'm just saying, as if you reduce the temperature of the diode too
much during operation, then light output may increase to the point
where damage may occur.
The bottom line is, keep the diode at a stable temperature, neither
too hot or too cool. Room temp would be just fine, just don`t take it
outside on a really cold day!
Leslie
Lostgallifreyan
news:et9fff$i2b$1...@ss408.t-com.hr:
> I'm from croatia btw so i don't have any shop in my
> country where i can buy hobbist stuff specialized for laser(like
> drivers) so probobly i need to order some just don't know where
> from...
>
Can you get an LM317 voltage regulator IC? If so, do it, and use the
formula 1.25/A to get your required resistor. A=0.40 for safe running, it
seems a 33 ohm resistor is the closest preferred value, and is higher that
the calculated 31.25 ohms, so don't worry if the resistor tolerance is not
as good as 1%. Most important, put a low ESR ceramic capacitor across the
diode if possible. Anything's better than nothing. Put a 0.1 湩 ceramic,
and a 10 湩 tatalum or low ESR electrolytic both in parallel with the laser
diode. This will drive it safely, but you won't get modulation without
adding stuff.
Lostgallifreyan
sheet for that device will show you how, it's an awesomely simple circuit
to build, and isn't fussy about supply voltage, so long as the IC can't
overheat.
Lostgallifreyan
news:1173910432.1...@e65g2000hsc.googlegroups.com:
> Don't make the diode too cool
> though, as this will drop the threshold current , and as its not going
> to be light feedback regulated, this could conceivably destroy the
> diode through COD (Catastrophic Optical Damage).
Good point, a heatsink is probably all that should be used. a TEC with red
diodes can shorten the wavelength and make it look brighter, but I think
the blues will also shorten, and in this case, that is not what we want. :)
Lostgallifreyan
news:1173916227.7...@l75g2000hse.googlegroups.com:
> How else should prevent COD?? AR lens?
>
Actually, that can be relevent, but only if you seriously overdrive the
diode to the point where only a small amount of retroreflection is needed
to provoke cavity mirror collapse. Just keep that current well-controlled
in safe area and the rest should take care of itself. Don't shine its light
back at it with a mirror though, we don't yet know if they can stand that.
Strong reds definitely can't.
Lostgallifreyan
news:Xns98F4493A7D8...@140.99.99.130:
> A=0.40 for safe running
NO... 0.04. Don't make the same error I just did!
Tom Cue
"Lostgallifreyan" <no-...@nowhere.net> wrote in message
news:Xns98F4499A9CC...@140.99.99.130...
Well guys, thanx a LOT...your advices are very helpfull to me. Yes, i have a
place where i can buy electronic component like LM317, i think even that a i
have couple of them at home...is there any smaller case than TO-220 of
LM317? Cause i dunno if i have so much place in side body for laser? Like
TO-252 or smaller?
Tom Cue
40 mA right....
Tom Cue
Now i'm confused...u mean that i use LM317 and not resistor?
Tom Cue
Dr Bob
as a constant current regulator. You should be able to google for the data
sheet. powering the laser through a resistor from a battery is a crude way
to regulate the current so use the LM317 as the regulating device you will
need the ic and a handfull of other components as per the data sheet. This
whole circuit will replace the resistor.
Also if you get an LM317LZ you can regulate up to 100mA with it & it will be
in a TO92 case like a transistor or LM317LM it will be in 8 pin SMD. the LZ
is easy to work with and should be readily available from your electronics
supplier. Just dont put too high a supply voltage in as the more volts
difference between the supply and the output the more heat the 317 will need
to get rid of. Although the 317 is thermally regulated you are better to
keep it out of the danger zone.
Rob
"Tom Cue" <tom.cue...@hi.t-com.hr> wrote in message
news:etb027$ri9$1...@ss408.t-com.hr...
>
Lostgallifreyan
Nice, that's exactly it, and as the other doctor (Bob) said, try a TO92
version, that will fit. Just watch for your voltage supply, it's more
critical that you take care to work out your heat dissipation. If you can
get it globbed to the inside of the shell with some kind of thermally
conductive epoxy you'll be safe, but there's still a maximum of 100 mA
capability, but that's plenty for the blue diode. What's interesting is the
TO92 form will work with higher power blues than reds, probably as they
have a higher voltage drop, allowing more energy to be shoved into them for
a given current.
Lostgallifreyan
news:Xns98F470872EF...@140.99.99.130:
> http://img252.imageshack.us/img252/2310/driverhq3.jpg
One small mod I suggest: change that resistor to a 0.6W metal film type.
The low noise and close tolerance will help you, and although the extra
power dissipation isn't needed here, it will be if you drive high power
single-mode reds.
leslie...@hotmail.com
Hi There,
yes I had for got to mention to use the LM317 as a
Constant current regulator!
The LM317 is available in a variety of packages. The LM317LZ is in a
TO-92 style case, which is much smaller than the TO-220.
rgds
Leslie
Tom Cue
Thanx a lot...one more question...there isn't tantalum capacitors at the
shop here...can u use ELKO thats not tantalum?
leslie...@hotmail.com
Tantalums store a lot more energy per unit volume, than say
electrolytics. Therefore a tantalum cap is much smaller than an
electrolytic of the same value. There may be other considerations with
this design such as leakage current.
rgds
Leslie
Lostgallifreyan
news:1173959885.5...@l75g2000hse.googlegroups.com:
> Tantalums store a lot more energy per unit volume, than say
> electrolytics. Therefore a tantalum cap is much smaller than an
> electrolytic of the same value. There may be other considerations with
> this design such as leakage current.
>
I used 406-9794 (RS Components stock number, low ESR SMT tantalum. 0.6渙
leakage, which looks good compared to the 3渙 quoted for a small
electrolytic. Both values 10湩, and the tantalum is SMALL, which is its
main weakness, if you're trying to build stuff, it's never going to work
unless you go to the trouble of making some way to mount it, you can't wire
it between component leads, in 'dead bug' wiring. Only some kind of board
will do it. I'm sure they make them with leads, but I never looked..
The main problem with tantalums might be accidental reverse voltage, but
that's bad for a laser too, so a diode in inverse parallel with the laser
diode is useful. I use a fast recovery type, but not a Schottky type, I
think they do have a leakage if reverse biased, I think I read somewhere..
Sam Goldwasser
> Forgot to add, use the LM317 as a CONSTANT CURRENT regulator. Any data
> sheet for that device will show you how, it's an awesomely simple circuit
> to build, and isn't fussy about supply voltage, so long as the IC can't
> overheat
Also, make sure to have generous filter capacitance after the regulator
and sense resistor.
And NEVER disconnect or connect the diode with power on and until you're
sure the capacitors are fully discharged.
--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html
Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
Lostgallifreyan
news:6whcsmt...@blue.seas.upenn.edu:
>> Forgot to add, use the LM317 as a CONSTANT CURRENT regulator. Any
>> data sheet for that device will show you how, it's an awesomely
>> simple circuit to build, and isn't fussy about supply voltage, so
>> long as the IC can't overheat
>
> Also, make sure to have generous filter capacitance after the
> regulator and sense resistor.
>
> And NEVER disconnect or connect the diode with power on and until
> you're sure the capacitors are fully discharged.
>
Indeed. :) I have done this, it's not fun. In addition to the low ESR 0.1湩
ceramic and low ESR 10湩 tantalum, I use a 'memcap' as a soft start device,
as it takes the current until it is charged enough to cease shunting any
away from the laser diode. As this cap is rated at 2.5V, and 1 Farad, it is
as much protected by the laser diode, as the laser diode is by this
capacitor. :) A neat symbiosis, I think... I never power up unless both are
securely connected. A 5V rated memcap (for those who don't know these,
they're used as CMOS memory backup supplies, hence the name) would be
needed for a blue diode, and might be too big for convenience. Also, if
using these, forget modulation because the capacitance is entirely too
generous, unless you want to modulate like an elderly drunk getting up in
the morning.
leslie...@hotmail.com
> Sam Goldwasser <s...@blue.seas.upenn.edu> wrote innews:6whcsmt...@blue.seas.upenn.edu:
>
> >> Forgot to add, use the LM317 as a CONSTANT CURRENT regulator. Any
> >> data sheet for that device will show you how, it's an awesomely
> >> simple circuit to build, and isn't fussy about supply voltage, so
> >> long as the IC can't overheat
>
> > Also, make sure to have generous filter capacitance after the
> > regulator and sense resistor.
>
> > And NEVER disconnect or connect the diode with power on and until
> > you're sure the capacitors are fully discharged.
>
> ceramic and low ESR 10µF tantalum, I use a 'memcap' as a soft start device,
> as it takes the current until it is charged enough to cease shunting any
> as much protected by thelaserdiode, as thelaserdiode is by this
> capacitor. :) A neat symbiosis, I think... I never power up unless both are
> securely connected. A 5V rated memcap (for those who don't know these,
> they're used as CMOS memory backup supplies, hence the name) would be
> needed for a blue diode, and might be too big for convenience. Also, if
> using these, forget modulation because the capacitance is entirely too
> generous, unless you want to modulate like an elderly drunk getting up in
> the morning.
I mailed roithner laser, they do driver IC's for Common Cathode Can
laser diodes.
They require a minimum of external components, and are very cheap at
4.40 Euros each.
$5.82 US
rgds
Leslie
Tom Cue
<leslie...@hotmail.com> wrote in message
news:1173978076.8...@e65g2000hsc.googlegroups.com...
On 15 Mar, 16:31, Lostgallifreyan <no-...@nowhere.net> wrote:
> Sam Goldwasser <s...@blue.seas.upenn.edu> wrote
> innews:6whcsmt...@blue.seas.upenn.edu:
>
> >> Forgot to add, use the LM317 as a CONSTANT CURRENT regulator. Any
> >> data sheet for that device will show you how, it's an awesomely
> >> simple circuit to build, and isn't fussy about supply voltage, so
> >> long as the IC can't overheat
>
> > Also, make sure to have generous filter capacitance after the
> > regulator and sense resistor.
>
> > And NEVER disconnect or connect the diode with power on and until
> > you're sure the capacitors are fully discharged.
>
> Indeed. :) I have done this, it's not fun. In addition to the low ESR
> ceramic and low ESR 10湩 tantalum, I use a 'memcap' as a soft start
> as it takes the current until it is charged enough to cease shunting any
> away from thelaserdiode. As this cap is rated at 2.5V, and 1 Farad, it is
> as much protected by thelaserdiode, as thelaserdiode is by this
> capacitor. :) A neat symbiosis, I think... I never power up unless both
> are
> securely connected. A 5V rated memcap (for those who don't know these,
> they're used as CMOS memory backup supplies, hence the name) would be
> needed for a blue diode, and might be too big for convenience. Also, if
> using these, forget modulation because the capacitance is entirely too
> generous, unless you want to modulate like an elderly drunk getting up in
> the morning.
I mailed roithner laser, they do driver IC's for Common Cathode Can
laser diodes.
They require a minimum of external components, and are very cheap at
4.40 Euros each.
$5.82 US
rgds
Leslie
Where can i order it?Do you have a part number or smthn
leslie...@hotmail.com
> <lesliewrig...@hotmail.com> wrote in message
>
> news:1173978076.8...@e65g2000hsc.googlegroups.com...
> On 15 Mar, 16:31, Lostgallifreyan <no-...@nowhere.net> wrote:
>
>
>
> > Sam Goldwasser <s...@blue.seas.upenn.edu> wrote
> > innews:6whcsmt...@blue.seas.upenn.edu:
>
> > >> Forgot to add, use the LM317 as a CONSTANT CURRENT regulator. Any
> > >> data sheet for that device will show you how, it's an awesomely
> > >> simple circuit to build, and isn't fussy about supply voltage, so
> > >> long as the IC can't overheat
>
> > > Also, make sure to have generous filter capacitance after the
> > > regulator and sense resistor.
>
> > > And NEVER disconnect or connect the diode with power on and until
> > > you're sure the capacitors are fully discharged.
>
> > Indeed. :) I have done this, it's not fun. In addition to the low ESR
> > ceramic and low ESR 10µF tantalum, I use a 'memcap' as a soft start
> > device,
> > as it takes the current until it is charged enough to cease shunting any
> > away from thelaserdiode. As this cap is rated at 2.5V, and 1 Farad, it is
> > as much protected by thelaserdiode, as thelaserdiode is by this
> > capacitor. :) A neat symbiosis, I think... I never power up unless both
> > are
> > securely connected. A 5V rated memcap (for those who don't know these,
> > they're used as CMOS memory backup supplies, hence the name) would be
> > needed for a blue diode, and might be too big for convenience. Also, if
> > using these, forget modulation because the capacitance is entirely too
> > generous, unless you want to modulate like an elderly drunk getting up in
> > the morning.
>
> I mailed roithner laser, they do driver IC's for Common Cathode Can
> laser diodes.
> They require a minimum of external components, and are very cheap at
> 4.40 Euros each.
> $5.82 US
>
> rgds
> Leslie
>
> Where can i order it?Do you have a part number or smthn
http://www.roithner-laser.com/Drivers.htm
There are a couple here. the CCC driver chip is part number iC-WKM,
its a surface mount job, but i dont think it would be too difficult to
solder with an ordinary iron. Plus its tiny!
They also have a complete CCC driver on that page too ($40USD I think)
Their ordering system is a little wierd, you e-mail them with what you
want, and where its going to. Then they mail you back with cost
+shipping (final quote) then you ring them up to give them your card
details!
It would be nice if thay had an online shop.
They sell all manner of laser-diode related components!
rgds
Leslie
leslie...@hotmail.com
an ordinary iron!"
leslie...@hotmail.com
an ordinary iron!"
leslie...@hotmail.com
today, and noticed, that as well as the reduced intensity of the beam,
there is also in incoherent greenish component. Has anyone seen this
in other damaged laser diodes?
rgds
Leslie
Dr Bob
midnight)
threshold like Leslie said around 27-28mA
then with LC set to 405nm
30mA 2.68mW
35mA 9.45mW
40mA 13.3mw
45mA 17.0mW
Will run some less hurried tests tomorrow and report
Rob
PS I dunno where they got the name Blu ray appart from it sounds better than
violet or purple ray
it most certainly isnt blue!
<leslie...@hotmail.com> wrote in message
news:1173995973.5...@n59g2000hsh.googlegroups.com...
leslie...@hotmail.com
> First results are in and it looks like this (quick and dirty test at
> midnight)
>
> threshold like Leslie said around 27-28mA
> then with LC set to 405nm
>
> 30mA 2.68mW
> 35mA 9.45mW
> 40mA 13.3mw
> 45mA 17.0mW
>
> Will run some less hurried tests tomorrow and report
>
> Rob
>
> PS I dunno where they got the name Blu ray appart from it sounds better than
> violet or purple ray
> it most certainly isnt blue!
>
GREAT STUFF!!!
looks like i wasnt too far off with my
initial estimate! I will add the data to the site in the morning, and
modify the graphs etc accordingly.
Now we're beginning to get a clearer picture of this devices
parameters.
By the way, regarding the colour, its realy very pleasing dont you
think? a lot less harsh than the 488 of an argon.
thanks
Leslie
James Sweet
A resistor will work, LM317 is better, you'll need resistors for that
too though.
Dr Bob
yesterday but was booked for an evening out :( so just did a quick ish test
which begun just before midnight. I still spent time taking photos mainly of
the disassembly of the unit. Ad of the fact that it lights up with a cool
purple glow at 0.5mA!
The biggest problem I had was getting the lasercheck in a suitable position
as the bracket that attaches the diode to the main chassis was getting in
the way and forcing me to hold the lasercheck either at an angle or too far
away to be certain of catching all the light. Tonight I will remove this and
get more consistent and comprehensive results mA per mA
As for the colour it is nice but very wierd and like blue and uv leds plays
little tricks on your eyes which seem not to be able to work out how to
focus on it properly. The best bit though is shining it around with no lens
and watching the purple flood of light pick out all the uv flourecent bits n
bobs.
very pretty indeed. I am gonna try combining it with red and green just to
see but not expecting it be be much use for an RGV whitelight.
Rob
<leslie...@hotmail.com> wrote in message
news:1174010620.0...@y66g2000hsf.googlegroups.com...
leslie...@hotmail.com
> As I said I will get some better results tonight - I got the delivery
> yesterday but was booked for an evening out :( so just did a quick ish test
> which begun just before midnight. I still spent time taking photos mainly of
> the disassembly of the unit. Ad of the fact that it lights up with a cool
> purple glow at 0.5mA!
> The biggest problem I had was getting the lasercheck in a suitable position
> as the bracket that attaches the diode to the main chassis was getting in
> the way and forcing me to hold the lasercheck either at an angle or too far
> away to be certain of catching all the light. Tonight I will remove this and
> get more consistent and comprehensive results mA per mA
> As for the colour it is nice but very wierd and like blue and uv leds plays
> little tricks on your eyes which seem not to be able to work out how to
> focus on it properly. The best bit though is shining it around with no lens
> and watching the purple flood of light pick out all the uv flourecent bits n
> bobs.
> very pretty indeed. I am gonna try combining it with red and green just to
> see but not expecting it be be much use for an RGV whitelight.
> Rob
>
Excellent, I will be looking forward to the results!
Leslie
Sam Goldwasser
> By the way, regarding the colour, its realy very pleasing dont you
> think? a lot less harsh than the 488 of an argon.
What are you seeing? 405 nm is deep violet, border of UV, appears about
1/200th the intensity of 555 nm peak eye sensitivity, 1/40th of a red HeNe.
If it appears blue at all, that's fluorescence on what it hits, or spurious
wavelengths in the beam. 405 nm is really really boring by itself.
Sam Goldwasser
For people wanting to use batteries, a resistor and a couple capacitors
may be better if they have no familiarity with regulators. :)
What's the voltage drop on these diodes?