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Is there an affordable UV photodiode?
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LM
Apr 21, 2012, 10:01:26 AM4/21/12
to
While reading posts about photodiodes and counting photons I noticed
that the topic is more than interesting, it could be useful.
I have a use to an affordable photodiode which is sensitive at around
300 – 100 nm. This is not for space craft or scientific instrument so
price is important.
By the way, if you are going to answer "yes" to my topic, please tell
the name of the diode or its manufacturer too, please.
Leif M
that the topic is more than interesting, it could be useful.
I have a use to an affordable photodiode which is sensitive at around
300 – 100 nm. This is not for space craft or scientific instrument so
price is important.
By the way, if you are going to answer "yes" to my topic, please tell
the name of the diode or its manufacturer too, please.
Leif M
Phil Hobbs
Apr 21, 2012, 11:02:49 AM4/21/12
to
long as they have quartz windows. Once you get down to 240 or
thereabouts, your options become a lot more limited, and of course 100
nm is vacuum ultraviolet, so you can't do anything very useful in air
except at very short ranges, which tends to be unhealthy. So you're
looking at probably three orders of magnitude difference in cost for
doing measurements across that range.
What are you hoping to do with it?
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
John Larkin
Apr 21, 2012, 11:07:33 AM4/21/12
to
On Sat, 21 Apr 2012 07:01:26 -0700 (PDT), LM <sala...@mail.com>
wrote:
Well, these people do everything but the "cheap" part. I'm using them
at 13 nm.
http://www.ird-inc.com/
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
wrote:
at 13 nm.
http://www.ird-inc.com/
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
LM
Apr 21, 2012, 12:33:18 PM4/21/12
to
On 21 huhti, 18:07, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Sat, 21 Apr 2012 07:01:26 -0700 (PDT), LM <sala.n...@mail.com>
I read from Wikipedia that every flame emits at these wavelenghts, so
what about a flame detector. A few meters or yards would be enough for
a distance.
>Well, these people do everything but the "cheap" part. I'm using them
at 13 nm.
Heh yes, I understand. But usually price and sales are inversely
proportional.
Leif
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Sat, 21 Apr 2012 07:01:26 -0700 (PDT), LM <sala.n...@mail.com>
> wrote:
>
> >While reading posts about photodiodes and counting photons I noticed
> >that the topic is more than interesting, it could be useful.
>
> >I have a use to an affordable photodiode which is sensitive at around
> >300 – 100 nm. This is not for space craft or scientific instrument so
> >price is important.
>
> >By the way, if you are going to answer "yes" to my topic, please tell
> >the name of the diode or its manufacturer too, please.
>
> >Leif M
>
> Well, these people do everything but the "cheap" part. I'm using them
> at 13 nm.
>
> http://www.ird-inc.com/
>
> --
>
> John Larkin Highland Technology Incwww.highlandtechnology.com jlarkin at highlandtechnology dot com
>
> >While reading posts about photodiodes and counting photons I noticed
> >that the topic is more than interesting, it could be useful.
>
> >I have a use to an affordable photodiode which is sensitive at around
> >300 – 100 nm. This is not for space craft or scientific instrument so
> >price is important.
>
> >By the way, if you are going to answer "yes" to my topic, please tell
> >the name of the diode or its manufacturer too, please.
>
> >Leif M
>
> Well, these people do everything but the "cheap" part. I'm using them
> at 13 nm.
>
> http://www.ird-inc.com/
>
> --
>
>
> Precision electronic instrumentation
> Picosecond-resolution Digital Delay and Pulse generators
> Custom timing and laser controllers
> Photonics and fiberoptic TTL data links
> VME analog, thermocouple, LVDT, synchro, tachometer
> Multichannel arbitrary waveform generators
Phil and John
> Precision electronic instrumentation
> Picosecond-resolution Digital Delay and Pulse generators
> Custom timing and laser controllers
> Photonics and fiberoptic TTL data links
> VME analog, thermocouple, LVDT, synchro, tachometer
> Multichannel arbitrary waveform generators
I read from Wikipedia that every flame emits at these wavelenghts, so
what about a flame detector. A few meters or yards would be enough for
a distance.
>Well, these people do everything but the "cheap" part. I'm using them
at 13 nm.
proportional.
Leif
John Larkin
Apr 21, 2012, 12:53:56 PM4/21/12
to
On Sat, 21 Apr 2012 09:33:18 -0700 (PDT), LM <sala...@mail.com>
wrote:
The gas-tube flame detectors are fairly cheap. They are breakdown
devices, so you power them from current-limited AC and look at the
resulting average current. They have only cudely linear response. The
ones I've used were sunlight blind but would fire from a lighted match
a couple of feet away.
There are semiconductor (silicon carbide?) flame detectors around now.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
wrote:
devices, so you power them from current-limited AC and look at the
resulting average current. They have only cudely linear response. The
ones I've used were sunlight blind but would fire from a lighted match
a couple of feet away.
There are semiconductor (silicon carbide?) flame detectors around now.
--
John Larkin Highland Technology Inc
John Larkin
Apr 21, 2012, 12:56:08 PM4/21/12
to
whit3rd
Apr 21, 2012, 1:57:13 PM4/21/12
to
On Saturday, April 21, 2012 7:01:26 AM UTC-7, LM wrote:
> I have a use to an affordable photodiode which is sensitive at around
> 300 – 100 nm. This is not for space craft or scientific instrument so
> price is important.
Well, the old vacuum-tube photocells are nearly ideal for this, but
> I have a use to an affordable photodiode which is sensitive at around
> 300 – 100 nm. This is not for space craft or scientific instrument so
> price is important.
why bother? Just put a fluorescent screen next to an IR through visible
photodiode/phototransistor/integrated sensor.
asdf
Apr 21, 2012, 6:39:07 PM4/21/12
to
Spehro Pefhany
Apr 22, 2012, 1:29:01 PM4/22/12
to
fOn Sat, 21 Apr 2012 11:02:49 -0400, the renowned Phil Hobbs
you double that up to ~120nm and just about see through metals?
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
<pcdhSpamM...@electrooptical.net> wrote:
>LM wrote:
>>
>> While reading posts about photodiodes and counting photons I noticed
>> that the topic is more than interesting, it could be useful.
>>
>> I have a use to an affordable photodiode which is sensitive at around
>> 300 – 100 nm. This is not for space craft or scientific instrument so
>> price is important.
>>
>> By the way, if you are going to answer "yes" to my topic, please tell
>> the name of the diode or its manufacturer too, please.
>>
>> Leif M
>
>300 nm is within the range of normal blue-enhanced silicon diodes, as
>long as they have quartz windows. Once you get down to 240 or
>thereabouts, your options become a lot more limited, and of course 100
>nm is vacuum ultraviolet, so you can't do anything very useful in air
>except at very short ranges, which tends to be unhealthy.
I see you can get UV LEDs down to ~240nm without much trouble. Could
>LM wrote:
>>
>> While reading posts about photodiodes and counting photons I noticed
>> that the topic is more than interesting, it could be useful.
>>
>> I have a use to an affordable photodiode which is sensitive at around
>> 300 – 100 nm. This is not for space craft or scientific instrument so
>> price is important.
>>
>> By the way, if you are going to answer "yes" to my topic, please tell
>> the name of the diode or its manufacturer too, please.
>>
>> Leif M
>
>300 nm is within the range of normal blue-enhanced silicon diodes, as
>long as they have quartz windows. Once you get down to 240 or
>thereabouts, your options become a lot more limited, and of course 100
>nm is vacuum ultraviolet, so you can't do anything very useful in air
>except at very short ranges, which tends to be unhealthy.
you double that up to ~120nm and just about see through metals?
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
Phil Hobbs
Apr 22, 2012, 3:01:35 PM4/22/12
to
Spehro Pefhany wrote:
>
> fOn Sat, 21 Apr 2012 11:02:49 -0400, the renowned Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
> >LM wrote:
> >>
> >> While reading posts about photodiodes and counting photons I noticed
> >> that the topic is more than interesting, it could be useful.
> >>
> >> I have a use to an affordable photodiode which is sensitive at around
> >> 300 – 100 nm. This is not for space craft or scientific instrument so
> >> price is important.
> >>
> >> By the way, if you are going to answer "yes" to my topic, please tell
> >> the name of the diode or its manufacturer too, please.
> >>
> >> Leif M
> >
> >300 nm is within the range of normal blue-enhanced silicon diodes, as
> >long as they have quartz windows. Once you get down to 240 or
> >thereabouts, your options become a lot more limited, and of course 100
> >nm is vacuum ultraviolet, so you can't do anything very useful in air
> >except at very short ranges, which tends to be unhealthy.
>
> I see you can get UV LEDs down to ~240nm without much trouble. Could
> you double that up to ~120nm and just about see through metals?
>
Frequency doubling LEDs is hard, because you can't get enough intensity
>
> fOn Sat, 21 Apr 2012 11:02:49 -0400, the renowned Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
> >LM wrote:
> >>
> >> While reading posts about photodiodes and counting photons I noticed
> >> that the topic is more than interesting, it could be useful.
> >>
> >> I have a use to an affordable photodiode which is sensitive at around
> >> 300 – 100 nm. This is not for space craft or scientific instrument so
> >> price is important.
> >>
> >> By the way, if you are going to answer "yes" to my topic, please tell
> >> the name of the diode or its manufacturer too, please.
> >>
> >> Leif M
> >
> >300 nm is within the range of normal blue-enhanced silicon diodes, as
> >long as they have quartz windows. Once you get down to 240 or
> >thereabouts, your options become a lot more limited, and of course 100
> >nm is vacuum ultraviolet, so you can't do anything very useful in air
> >except at very short ranges, which tends to be unhealthy.
>
> I see you can get UV LEDs down to ~240nm without much trouble. Could
> you double that up to ~120nm and just about see through metals?
>
in the crystal for good efficiency. (There aren't that many crystals
that work at 120 nm, either--I can't think of one off-hand, but then I'm
a plain vanilla CW guy whenever possible.)
And IIRC it's really only alkali metals that become reasonably
transparent in the UV, though there may be a few others. Even that
would be pretty cool, though--I've never seen the experiment done.
Spehro Pefhany
Apr 23, 2012, 4:28:39 PM4/23/12
to
above the plasma frequency.
There's a lot of variation in the reported numbers on the net- due to
the ne (carrier density)?
There's a cool relationship between the plasma frequency and the
London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
equal to!
k...@att.bizzzzzzzzzzzz
Apr 23, 2012, 9:03:37 PM4/23/12
to
>There's a lot of variation in the reported numbers on the net- due to
>the ne (carrier density)?
>
>There's a cool relationship between the plasma frequency and the
>London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
>equal to!
Spehro Pefhany
Apr 24, 2012, 12:06:52 PM4/24/12
to
On Mon, 23 Apr 2012 21:03:37 -0400, "k...@att.bizzzzzzzzzzzz"
<k...@att.bizzzzzzzzzzzz> wrote:
>
>>
>>There's a cool relationship between the plasma frequency and the
>>London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
>>equal to!
>
>Si Señor, but I don't see the relationship.
There's a kind of inductance due to the kinetic energy of the
<k...@att.bizzzzzzzzzzzz> wrote:
>
>>
>>There's a cool relationship between the plasma frequency and the
>>London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
>>equal to!
>
>Si Señor, but I don't see the relationship.
carriers. It doesn't usually affect room temperature electrical
conduction in metals measurably because the carriers never get a
chance to get moving very fast- they typically bump into something
every 0.1ps or so ("relaxation time" in the Drude model of
conductivity).
At really high frequencies (such as ~100nm hard UV) the kinetic
reactance becomes important relative to the resistance in typical
metals, or if the resistivity goes to zero (as in a superconductor) it
also becomes important. In the latter case, it allows the wave to
penetrate into the conductor (typically by ~100nm or so).
k...@att.bizzzzzzzzzzzz
Apr 24, 2012, 9:22:12 PM4/24/12
to
On Tue, 24 Apr 2012 12:06:52 -0400, Spehro Pefhany
<spef...@interlogDOTyou.knowwhat> wrote:
>On Mon, 23 Apr 2012 21:03:37 -0400, "k...@att.bizzzzzzzzzzzz"
><k...@att.bizzzzzzzzzzzz> wrote:
>
>>
>>>
>>>There's a cool relationship between the plasma frequency and the
>>>London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
>>>equal to!
>>
>>Si Señor, but I don't see the relationship.
>
>There's a kind of inductance due to the kinetic energy of the
>carriers. It doesn't usually affect room temperature electrical
>conduction in metals measurably because the carriers never get a
>chance to get moving very fast- they typically bump into something
>every 0.1ps or so ("relaxation time" in the Drude model of
>conductivity).
Inductance? I'd think it was more of a resistance. Energy can be stored?
<spef...@interlogDOTyou.knowwhat> wrote:
>On Mon, 23 Apr 2012 21:03:37 -0400, "k...@att.bizzzzzzzzzzzz"
><k...@att.bizzzzzzzzzzzz> wrote:
>
>>
>>>
>>>There's a cool relationship between the plasma frequency and the
>>>London depth in superconductors. Reminded me what 1/sqrt(u0 * e0) is
>>>equal to!
>>
>>Si Señor, but I don't see the relationship.
>
>There's a kind of inductance due to the kinetic energy of the
>carriers. It doesn't usually affect room temperature electrical
>conduction in metals measurably because the carriers never get a
>chance to get moving very fast- they typically bump into something
>every 0.1ps or so ("relaxation time" in the Drude model of
>conductivity).
>At really high frequencies (such as ~100nm hard UV) the kinetic
>reactance becomes important relative to the resistance in typical
>metals, or if the resistivity goes to zero (as in a superconductor) it
>also becomes important. In the latter case, it allows the wave to
>penetrate into the conductor (typically by ~100nm or so).
Spehro Pefhany
Apr 24, 2012, 10:24:37 PM4/24/12
to
On Tue, 24 Apr 2012 21:22:12 -0400, the renowned
"k...@att.bizzzzzzzzzzzz" <k...@att.bizzzzzzzzzzzz> wrote:
>
>>There's a kind of inductance due to the kinetic energy of the
>>carriers. It doesn't usually affect room temperature electrical
>>conduction in metals measurably because the carriers never get a
>>chance to get moving very fast- they typically bump into something
>>every 0.1ps or so ("relaxation time" in the Drude model of
>>conductivity).
>
>Inductance? I'd think it was more of a resistance. Energy can be stored?
Sure, kinetic energy, on top of the energy stored in the magnetic
"k...@att.bizzzzzzzzzzzz" <k...@att.bizzzzzzzzzzzz> wrote:
>
>>There's a kind of inductance due to the kinetic energy of the
>>carriers. It doesn't usually affect room temperature electrical
>>conduction in metals measurably because the carriers never get a
>>chance to get moving very fast- they typically bump into something
>>every 0.1ps or so ("relaxation time" in the Drude model of
>>conductivity).
>
>Inductance? I'd think it was more of a resistance. Energy can be stored?
field.
>>At really high frequencies (such as ~100nm hard UV) the kinetic
>>reactance becomes important relative to the resistance in typical
>>metals, or if the resistivity goes to zero (as in a superconductor) it
>>also becomes important. In the latter case, it allows the wave to
>>penetrate into the conductor (typically by ~100nm or so).
>
>Transparent aluminum. Huh. Hadn't noticed that phenomenon. ;-)
in the back of the comic books.
http://tomheroes.com/images/COMICAD%20xray%20glasses.JPG
Tim Williams
Apr 24, 2012, 10:25:58 PM4/24/12
to
<k...@att.bizzzzzzzzzzzz> wrote in message
news:qakep7lq8chvcs1a0...@4ax.com...
"transparent", but the light which shines through is nonetheless -- blue! :)
Wonder how much is lost to refraction. Obviously, CDs are quite shiny.
Could thin layers of metal, separated by dielectric layers, provide a good
match to free space while filtering light in a useful way?
Reminds me of something I was reading about recently that was talking about
nanometer layers of gold. Can't remember what it was actually about.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
news:qakep7lq8chvcs1a0...@4ax.com...
>>At really high frequencies (such as ~100nm hard UV) the kinetic
>>reactance becomes important relative to the resistance in typical
>>metals, or if the resistivity goes to zero (as in a superconductor) it
>>also becomes important. In the latter case, it allows the wave to
>>penetrate into the conductor (typically by ~100nm or so).
>
> Transparent aluminum. Huh. Hadn't noticed that phenomenon. ;-)
Never held up a CD to the light? The layer is a bit thicker than
>>reactance becomes important relative to the resistance in typical
>>metals, or if the resistivity goes to zero (as in a superconductor) it
>>also becomes important. In the latter case, it allows the wave to
>>penetrate into the conductor (typically by ~100nm or so).
>
> Transparent aluminum. Huh. Hadn't noticed that phenomenon. ;-)
"transparent", but the light which shines through is nonetheless -- blue! :)
Wonder how much is lost to refraction. Obviously, CDs are quite shiny.
Could thin layers of metal, separated by dielectric layers, provide a good
match to free space while filtering light in a useful way?
Reminds me of something I was reading about recently that was talking about
nanometer layers of gold. Can't remember what it was actually about.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
k...@att.bizzzzzzzzzzzz
Apr 24, 2012, 11:03:01 PM4/24/12
to
On Tue, 24 Apr 2012 21:25:58 -0500, "Tim Williams" <tmor...@gmail.com>
wrote:
><k...@att.bizzzzzzzzzzzz> wrote in message
>news:qakep7lq8chvcs1a0...@4ax.com...
>>>At really high frequencies (such as ~100nm hard UV) the kinetic
>>>reactance becomes important relative to the resistance in typical
>>>metals, or if the resistivity goes to zero (as in a superconductor) it
>>>also becomes important. In the latter case, it allows the wave to
>>>penetrate into the conductor (typically by ~100nm or so).
>>
>> Transparent aluminum. Huh. Hadn't noticed that phenomenon. ;-)
>
>Never held up a CD to the light? The layer is a bit thicker than
>"transparent", but the light which shines through is nonetheless -- blue! :)
>
>Wonder how much is lost to refraction. Obviously, CDs are quite shiny.
You mean reflection? There should be no significant refraction, the sides are
flat and parallel.
>Could thin layers of metal, separated by dielectric layers, provide a good
>match to free space while filtering light in a useful way?
You mean like sun glasses? ;-)
>Reminds me of something I was reading about recently that was talking about
>nanometer layers of gold. Can't remember what it was actually about.
Isn't gold used for anti-reflective coatings on glass (gold-colored building
glass isn't uncommon)? Partially aluminized surfaces are used for beam
splitters and "one-way" mirrors.
I'm pretty sure Spehro is talking about a different phenomenon, though.
wrote:
><k...@att.bizzzzzzzzzzzz> wrote in message
>news:qakep7lq8chvcs1a0...@4ax.com...
>>>At really high frequencies (such as ~100nm hard UV) the kinetic
>>>reactance becomes important relative to the resistance in typical
>>>metals, or if the resistivity goes to zero (as in a superconductor) it
>>>also becomes important. In the latter case, it allows the wave to
>>>penetrate into the conductor (typically by ~100nm or so).
>>
>> Transparent aluminum. Huh. Hadn't noticed that phenomenon. ;-)
>
>Never held up a CD to the light? The layer is a bit thicker than
>"transparent", but the light which shines through is nonetheless -- blue! :)
>
>Wonder how much is lost to refraction. Obviously, CDs are quite shiny.
flat and parallel.
>Could thin layers of metal, separated by dielectric layers, provide a good
>match to free space while filtering light in a useful way?
>Reminds me of something I was reading about recently that was talking about
>nanometer layers of gold. Can't remember what it was actually about.
glass isn't uncommon)? Partially aluminized surfaces are used for beam
splitters and "one-way" mirrors.
I'm pretty sure Spehro is talking about a different phenomenon, though.
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