Counting photons with an MPPC

[Phil Hobbs]

Well, the MPPC demo system is done. It has four of our small
proprietary boards (controller/SMPS, TEC driver, voltage-controlled
amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
and a box of voltage regulators. Works from single photons up to about
4 mA in one range.

This video shows it counting photons, which I still think is a cool
thing to be able to do.

<https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

[John Larkin]

On Wed, 21 Aug 2019 18:18:53 -0400, Phil Hobbs
<pcdhSpamM...@electrooptical.net> wrote:

>Well, the MPPC demo system is done. It has four of our small
>proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>and a box of voltage regulators. Works from single photons up to about
>4 mA in one range.
>
>This video shows it counting photons, which I still think is a cool
>thing to be able to do.
>
><https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>
>Cheers
>
>Phil Hobbs

That's pretty sensitive to voltage. What's the background count rate
like?

Why is your workbench so neat?

[Phil Hobbs]

On 8/21/19 6:28 PM, John Larkin wrote:
> On Wed, 21 Aug 2019 18:18:53 -0400, Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
>> Well, the MPPC demo system is done. It has four of our small
>> proprietary boards (controller/SMPS, TEC driver,
>> voltage-controlled amplifier, and APD bias) plus a handwired
>> pHEMT-boostrapped front end and a box of voltage regulators. Works
>> from single photons up to about 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a
>> cool thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

>

> That's pretty sensitive to voltage.

It sure is. Gain doubles in roughly a volt.

> What's the background count rate like?

About 200 kHz at room temperature, maybe 10 kHz at -10C, which is where
it's set to. For the cathodoluminescence application it hardly matters
because you need > 2 MHz count rates to get a decent image in a
reasonable time.

>
> Why is your workbench so neat?

<https://www.gocomics.com/calvinandhobbes/1992/09/17/> ;)

[jla...@highlandsniptechnology.com]

On Wed, 21 Aug 2019 19:00:51 -0400, Phil Hobbs

<pcdhSpamM...@electrooptical.net> wrote:

>On 8/21/19 6:28 PM, John Larkin wrote:
>> On Wed, 21 Aug 2019 18:18:53 -0400, Phil Hobbs
>> <pcdhSpamM...@electrooptical.net> wrote:
>>
>>> Well, the MPPC demo system is done. It has four of our small
>>> proprietary boards (controller/SMPS, TEC driver,
>>> voltage-controlled amplifier, and APD bias) plus a handwired
>>> pHEMT-boostrapped front end and a box of voltage regulators. Works
>>> from single photons up to about 4 mA in one range.
>>>
>>> This video shows it counting photons, which I still think is a
>>> cool thing to be able to do.
>>>
>>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>
>>
>> That's pretty sensitive to voltage.
>
>It sure is. Gain doubles in roughly a volt.
>
>> What's the background count rate like?
>
>About 200 kHz at room temperature, maybe 10 kHz at -10C, which is where
>it's set to. For the cathodoluminescence application it hardly matters
>because you need > 2 MHz count rates to get a decent image in a
>reasonable time.
>
>>
>> Why is your workbench so neat?
>
><https://www.gocomics.com/calvinandhobbes/1992/09/17/> ;)
>
>Cheers
>
>Phil Hobbs

When I was a kid, I slept on a tiny strip of my bed. The rest was
covered with electronics. My mom wouldn't go into my room for years.

[Phil Hobbs]

I had to keep my stuff on the floor, because otherwise the cat would
have gradually pushed me off the edge. ;)

Cheers

Phil Hobbs

(Whose most recent cat shuffled off this mortal coil about 15 years ago.)

[jla...@highlandsniptechnology.com]

On Wed, 21 Aug 2019 19:45:33 -0400, Phil Hobbs

I've known women like that.

[Phil Hobbs]

But that's a good thing, unlike the cat.

Cheers

Phil Hobbs

[George Herold]

On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:
> Well, the MPPC demo system is done. It has four of our small
> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
> and a box of voltage regulators. Works from single photons up to about
> 4 mA in one range.
>
> This video shows it counting photons, which I still think is a cool
> thing to be able to do.
>
> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

Not loading here...
(OK got it.. pretty cool.)
I've been thinking, reading about photon counting.
Detector efficiency has to be the number one parameter..
(well maybe with time resolution.. short spikey pulses.)

Some of the papers are ~1/2 right, and then miss efficiency.

You've been talking about some photon counting 'white paper'
I hope it has a section on correlated photons.
There's this fact that accidentals go as the flux squared,
and the signal goes as the flux (number of photons.)
So.. given some time resolution, there's an optimal flux..
(signal to noise) that is in between zero and infinity.

George H.

[Phil Hobbs]

On 8/21/19 10:16 PM, George Herold wrote:
> On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:
>> Well, the MPPC demo system is done. It has four of our small
>> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>> and a box of voltage regulators. Works from single photons up to about
>> 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a cool
>> thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
> Not loading here...
> (OK got it.. pretty cool.)
> I've been thinking, reading about photon counting.
> Detector efficiency has to be the number one parameter..
> (well maybe with time resolution.. short spikey pulses.)

Efficiency times fill factor, right.

>
> Some of the papers are ~1/2 right, and then miss efficiency.

But then they would, wouldn't they?

>
> You've been talking about some photon counting 'white paper'
> I hope it has a section on correlated photons.


> There's this fact that accidentals go as the flux squared,
> and the signal goes as the flux (number of photons.)
> So.. given some time resolution, there's an optimal flux..
> (signal to noise) that is in between zero and infinity.

Dunno how to quantify that in general, but it's definitely worth
thinking about.

Cheers

Phil Hobb

[Robert Baer]

Phil Hobbs wrote:
> Well, the MPPC demo system is done.  It has four of our small
> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
> and a box of voltage regulators.  Works from single photons up to about
> 4 mA in one range.
>
> This video shows it counting photons, which I still think is a cool
> thing to be able to do.
>
> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>
> Cheers
>
> Phil Hobbs
>

What would be beyond "mere" counting, is to listen to their fuzzy
gyrations, the singing, the buzz; in effect, the random existence in a
given space.

[Jan Panteltje]

On a sunny day (Wed, 21 Aug 2019 18:18:53 -0400) it happened Phil Hobbs
<pcdhSpamM...@electrooptical.net> wrote in
<qjkg0h$cl8$1...@dont-email.me>:

>Well, the MPPC demo system is done. It has four of our small
>proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>and a box of voltage regulators. Works from single photons up to about
>4 mA in one range.
>
>This video shows it counting photons, which I still think is a cool
>thing to be able to do.
>
><https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

That movie is a typical waste of bandwidth,
it could be done in a few MB with decent compression.

Before publishing be so kind as to point out the fileseze for those on slower links and limited budget data.
Add some subtitles if explanation is needed.


See
http://panteltje.com/pub/PMT_FEU35_interface_mvi_3210.avi
597440 bytes
Analog scopes do not lie either :-)


Yours:
# mediainfo MPPCphotonCounting.mts
General
ID : 0
Complete name : MPPCphotonCounting.mts
Format : BDAV
Format/Info : BluRay Video
File size : 136 MiB
Duration : 1mn 18s
Overall bit rate : 14.5 Mbps
Maximum Overall bit rate : 18.0 Mbps

Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : No
Format settings, ReFrames : 2 frames
Duration : 1mn 18s
Bit rate : 13.7 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16/9
Frame rate : 29.970 fps
Resolution : 24 bits
Colorimetry : 4:2:0
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.221
Stream size : 129 MiB (95%)

Audio
ID : 4352 (0x1100)
Menu ID : 1 (0x1)
Format : AC-3
Format/Info : Audio Coding 3
Duration : 1mn 18s
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48.0 KHz
Stream size : 1.80 MiB (1%)

Text
ID : 4608 (0x1200)
Menu ID : 1 (0x1)
Format : PGS
Duration : 1mn 18s

[Phil Hobbs]

On 8/22/19 4:27 AM, Jan Panteltje wrote:
> On a sunny day (Wed, 21 Aug 2019 18:18:53 -0400) it happened Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote in
> <qjkg0h$cl8$1...@dont-email.me>:
>
>> Well, the MPPC demo system is done. It has four of our small
>> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>> and a box of voltage regulators. Works from single photons up to about
>> 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a cool
>> thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>
> That movie is a typical waste of bandwidth,
> it could be done in a few MB with decent compression.

Kiss my grits. ;)

Cheers

Phil Hobbs

[Joseph Gwinn]

On Aug 21, 2019, Phil Hobbs wrote
(in article <qjkg0h$cl8$1...@dont-email.me>):

> Well, the MPPC demo system is done. It has four of our small
> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
> and a box of voltage regulators. Works from single photons up to about
> 4 mA in one range.
>
> This video shows it counting photons, which I still think is a cool
> thing to be able to do.
>
> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

What kind of file is this? It promptly crashes on my computer (MacOS). It
appears to have asked for permission to control my computer, specifically
through the accessibility features, which are turned off for security
reasons.

Joe Gwinn

[DecadentLinux...@decadence.org]

Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote in

news:qjm351$qla$1...@dont-email.me:

They are looking at single photon spurt devices (for lack of
knowledge of the right term) in the quantum computing realm.

We made power supplies (dynode) for PMTs that are on the F-4
airframe thast can detect single photon events, such as a missile
launch. That is decades old tech.

But the counting thing...

The quantum computer guys like photonic qbits.

"Only God can count that fast..." --unknown

As to the video, I do not know what to do with an mts file.

[Phil Hobbs]

Run VLC on it. Anything with an H.264 codec should work. (It's the
file format my camera produces natively.)

[Phil Hobbs]

On 8/21/19 6:18 PM, Phil Hobbs wrote:

Everybody's a critic. ;) I converted it to mpeg and amended the link.

> Well, the MPPC demo system is done.  It has four of our small
> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
> and a box of voltage regulators.  Works from single photons up to about
> 4 mA in one range.
>
> This video shows it counting photons, which I still think is a cool
> thing to be able to do.
>

> <https://electrooptical.net/www/sed/MPPCphotonCounting.mpg>

[jjhu...@gmail.com]

lol, then there are those who are not well informed. VLC is the answer to playing almost any video format. Learned about it long time ago. Great program.

[DecadentLinux...@decadence.org]

Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote in

news:qjm6cf$e8q$1...@dont-email.me:

> On 8/21/19 6:18 PM, Phil Hobbs wrote:
>
> Everybody's a critic. ;) I converted it to mpeg and amended the
> link.
>
>> Well, the MPPC demo system is done.  It has four of our small
>> proprietary boards (controller/SMPS, TEC driver,
>> voltage-controlled amplifier, and APD bias) plus a handwired
>> pHEMT-boostrapped front end and a box of voltage regulators. 
>> Works from single photons up to about 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a
>> cool thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mpg>
>>
>> Cheers
>>
>> Phil Hobbs
>>

I just got done watching it with VLC. Why the assocoation wsa gone
I do not know.

But I never complained...

[DecadentLinux...@decadence.org]

jjhu...@gmail.com wrote in
news:0490f492-9c27-4f56...@googlegroups.com:

> lol, then there are those who are not well informed. VLC is the
> answer to playing almost any video format. Learned about it long
> time ago. Great program.
>

I have been using it since it forst came out. I am pretty sure I
know as much about video as you.

I used to work on the first MPEG-2 satellite equipment.

Not a tech at a TV station.

I was at General Instrument. They went on to develop HDTV.

[Jan Panteltje]

On a sunny day (Thu, 22 Aug 2019 08:51:45 -0400) it happened Phil Hobbs
<pcdhSpamM...@electrooptical.net> wrote in
<qjm351$qla$1...@dont-email.me>:

A typical example of bandwidth waste,
picture is of a static object, only a minuscule scope display has some motion,

AND WE ALL KNOW THERE IS JUST A 555 TIMER AND A POTMETER IN THOSE CLOSED BOXES
;-)

>Cheers

Do not drink so much.


>Phil Hobbs
>

[jjhu...@gmail.com]

On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:

Please excuse this naive question as this is not my background, but....
What kind of detector is being used? how do you know if you missed a photon? have two or more coincident ones? or miscounted? e.g. false positives and false negatives.
If my recollection from college physics is correct, a photon has a certain energy level. Do all photons have the same energy level or do they vary? I would imagine if they can contain different energy levels then discriminating between n>1 hits would be very tricky.
Yea, it is cool to count them - thanks for sharing.
J

[George Herold]

That's OK. I'm sorta thinking about it... there's probably a good paper somewhere.
Here is the classic paper by Aspect etal, it gets everything right...
Some later papers seem confused... but the confusion could be in me. :^)
http://www.lac.u-psud.fr/IMG/pdf/anticorrelation_epl.pdf

Figure 2.

If you run at very low count rates, you get no accidentals, but it takes longer to
get enough counts.. and you also run into the dark counts from your detector.

George H.

[jjhu...@gmail.com]

You probably do know more than me in this area. At one point in my work I was dealing with developing object detection methods (based on various mathematical and ANN classifiers) from many different video formats.
My only point was, of all the programs and tools that I used (or wrote/augmented), VLC was able to play just about any format. That was some time ago and things may have changed, but it still serves me well.
J

[Jan Panteltje]

On a sunny day (Thu, 22 Aug 2019 06:50:58 -0700 (PDT)) it happened
jjhu...@gmail.com wrote in
<0490f492-9c27-4f56...@googlegroups.com>:

>On Thursday, August 22, 2019 at 9:47:01 AM UTC-4, Phil Hobbs wrote:
>> On 8/21/19 6:18 PM, Phil Hobbs wrote:
>>
>> Everybody's a critic. ;) I converted it to mpeg and amended the link.
>>

>> > Well, the MPPC demo system is done.=C2=A0 It has four of our small

>> > proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>> > amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>>

>> and a box of voltage regulators.=C2=A0 Works from single photons up to about

>>
>> 4 mA in one range.
>> >
>> > This video shows it counting photons, which I still think is a cool
>> > thing to be able to do.
>> >
>> > <https://electrooptical.net/www/sed/MPPCphotonCounting.mpg>
>> >
>> > Cheers
>> >
>> > Phil Hobbs
>> >
>>
>>
>> --
>> Dr Philip C D Hobbs
>> Principal Consultant
>> ElectroOptical Innovations LLC / Hobbs ElectroOptics
>> Optics, Electro-optics, Photonics, Analog Electronics
>> Briarcliff Manor NY 10510
>>
>> http://electrooptical.net
>> http://hobbs-eo.com
>
>lol, then there are those who are not well informed. VLC is the answer to playing
>almost any video format. Learned about it long time ago. Great program.

VLC is a disaster, removed it long ago, does not even run as root here,
from kindergarten for kindergarten.

Use mplayer ffplay, xine.
mplayer plays it without problems, even a 6 years old version.
ffmpeg to convert it to someting of normal size.

Just imagine poor Joerg downloading that movie
it would use up a year of his data package.

[Jan Panteltje]

On a sunny day (Thu, 22 Aug 2019 07:09:45 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<b3786f54-87c2-4607...@googlegroups.com>:

>That's OK. I'm sorta thinking about it... there's probably a good paper somewhere.
>Here is the classic paper by Aspect etal, it gets everything right...
>Some later papers seem confused... but the confusion could be in me. :^)
>http://www.lac.u-psud.fr/IMG/pdf/anticorrelation_epl.pdf
>
>Figure 2.
>
>If you run at very low count rates, you get no accidentals, but it takes longer to
>get enough counts.. and you also run into the dark counts from your detector.
>
>George H.

The way I see it,
1)
photon is just a mathematical construct,

2)
Imagine an ocean full of waves
in it a pole (atom) with a ball (electron) connected to it with a feeble thin wire.
The PMT or whatever semiconductor or ANY detector that detects single electron events
now is a ball detector.

THE BALL WILL BREAK LOSE WHEN THE TOTAL ENERGY PHASE AND AMPLITUDE of the sum of every event in the universe is just right,
Fishysicks then claim 'photon detected'.

So it is in fact also affected by the Voyager spacecraft sending data home.
Sum of waves.

Some then say 'my signal and noise', where my signal is the extra ripples they just created in the pool
by throwing their study book in for example.


I think Planck gave a clear warning that A.E. ignored?


grrrr

[George Herold]

On Thursday, August 22, 2019 at 10:37:51 AM UTC-4, Jan Panteltje wrote:
> On a sunny day (Thu, 22 Aug 2019 07:09:45 -0700 (PDT)) it happened George
> Herold <ghe...@teachspin.com> wrote in
> <b3786f54-87c2-4607...@googlegroups.com>:
>
> >That's OK. I'm sorta thinking about it... there's probably a good paper somewhere.
> >Here is the classic paper by Aspect etal, it gets everything right...
> >Some later papers seem confused... but the confusion could be in me. :^)
> >http://www.lac.u-psud.fr/IMG/pdf/anticorrelation_epl.pdf
> >
> >Figure 2.
> >
> >If you run at very low count rates, you get no accidentals, but it takes longer to
> >get enough counts.. and you also run into the dark counts from your detector.
> >
> >George H.
>
> The way I see it,
> 1)
> photon is just a mathematical construct,
>
> 2)
> Imagine an ocean full of waves
> in it a pole (atom) with a ball (electron) connected to it with a feeble thin wire.
> The PMT or whatever semiconductor or ANY detector that detects single electron events
> now is a ball detector.

So these correlated light sources (typically parametric down conversion X-tal)
are a little different. Though I'm still figuring out exactly 'what' is different.

You can't push a button and get a photon... but you can get a detection in one
arm, and then know there is a photon in the other arm. This let's you look
for correlations over a very small time window... which changes the statistics
(somehow). As I said it's not clear to me yet.

George H.

[Phil Hobbs]

On 8/22/19 10:08 AM, jjhu...@gmail.com wrote:
> On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:
>> Well, the MPPC demo system is done. It has four of our small
>> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>> and a box of voltage regulators. Works from single photons up to about
>> 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a cool
>> thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>>
>> Cheers
>>
>> Phil Hobbs
>>
>> --
>> Dr Philip C D Hobbs
>> Principal Consultant
>> ElectroOptical Innovations LLC / Hobbs ElectroOptics
>> Optics, Electro-optics, Photonics, Analog Electronics
>> Briarcliff Manor NY 10510
>>
>> http://electrooptical.net
>> http://hobbs-eo.com
>
> Please excuse this naive question as this is not my background, but....
> What kind of detector is being used?

It's a Hamamatsu S13362-3050. The product will use a tiled array.

how do you know if you missed a photon? have two or more coincident
ones? or miscounted? e.g. false positives and false negatives.

You miss most of the photons. The probability of detection is only
about 40% at most, and only 74% of the area is active. It's roughly
competitive with a PMT.

> If my recollection from college physics is correct, a photon has a certain energy level. Do all photons have the same energy level or do they vary?

They vary. Energy is hc/lambda.

>I would imagine if they can contain different energy levels then discriminating >between n>1 hits would be very tricky.

The pulse height doesn't depend on the photon energy.

> Yea, it is cool to count them - thanks for sharing.

[Steve Wilson]

Phil Hobbs <pcdhSpamM...@electrooptical.net> wrote:

> The pulse height doesn't depend on the photon energy.

>> Yea, it is cool to count them - thanks for sharing.

> Cheers

> Phil Hobbs

OT, but may be of interest.

"Identical photons generated 150 million kilometers apart"

https://arstechnica.com/science/2019/08/identical-photons-generated-150-
million-kilometers-apart/

[gray_wolf]

VLC works for me. :-)

[Jan Panteltje]

On a sunny day (Thu, 22 Aug 2019 08:04:20 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<5b894822-c721-4f6b...@googlegroups.com>:

Sure, should that surprise me?
I look at it all from a wave perspective.
QM was shown to be a joke a while ago (something about no more cats etc, was posted here).

OK, will look it up
https://www.sciencedaily.com/releases/2019/06/190603124621.htm

This from an old posting


<start quoting from old posting>

On a sunny day (Tue, 30 May 06 10:55:37 GMT) it happened lpa...@emory.edu
(Lloyd Parker) wrote in <e5hmdb$ajs$2...@leto.cc.emory.edu>:

>>Max Planck,
>>the originator of light quanta. In his recorded remarks which
>>took place during 1909 in an audience at Einstein's talk we see him
>>resisting Einstein's hypothesis of atomistic light quanta propagation
>>through space. "If Einstein were correct, how could one account for
>>interference when the length over which one detected interference was many
>>thousands of wavelengths? How could a quantum of light interfere with itself
>>over such great distances if it were a point object? Instead of quantized
>>electromagnetic fields, one should attempt to transfer the whole problem of
>>the quantum theory to the area of INTERACTION between matter and radiation
>>energy".
>>
>>(I stole this from http://www.blazelabs.com/f-g-dist.asp ).

<end quoting old posting>


Again, I am no fishysicks so my 'world view' is somewhat less mathemagical.

I always want a mechanism.

OTOH I remember as a kid with my father we build a simple synchronous electric motor,
with a kit called 'mecano' here.
Basically a wheel with metal side tabs and a 50 Hz electromagnet
Spin the wheel and it would run in sync with the 50 Hz field.

I asked my father 'what exactly is that magnetic force, what causes it, how does it work?'
My father said: You will earn that later at school'
He would react that way if he did not know the answer.
I never learned it, just a bunch of ideas..
We do not even know what an electron is, why those repel each other (usually, seems in super-conductors those pair up,
and there was also the 'electron black hole' and I have actually seen a ball lightning hanging in front of me,
IMNSHO opinion that WAS an electron black hole, Murat Ozer is the one that proposed that see
https://arxiv.org/abs/gr-qc/9911011
and so many other things, we know, shit really.
Twenty first century science
take it for what it is worth.
But it IS fun!

[George Herold]

Yeah I remember seeing that... Some physics types are concerned about
'the measurement problem'.. they don't have a model for how a measurement
works. But that doesn't really bother me. (I mean you can't make a
QM model of a PMT... but so what.)

Hey I found a decent rev. sci. I. article about single phton sources and detectors.
https://www.dropbox.com/s/1ud9byktcermyvy/single-photon.pdf?dl=0
(I'm sharing it for educational purposes only.)

I never knew there were so many... and that was from 2011.

George H.

[Joseph Gwinn]

On Aug 22, 2019, Phil Hobbs wrote
(in article <qjm6cf$e8q$1...@dont-email.me>):

> On 8/21/19 6:18 PM, Phil Hobbs wrote:
>
> Everybody's a critic. ;) I converted it to mpeg and amended the link.

Well, I figured out what was happening on my iMac (running MacOS 10.14.5).

The default application to handle a ".mht´ file is "MPlayerX.app",
which I never heard of: "Copyright © 2009-2016, Zongyao QU." Well, from
file dates, I must have installed it in 2016, but don´t recall why. Google.
It´s an omnivorous media player - I must have been trying to read some kind
of movie file and failing. In any event, MPlayerX did not know what to do
with a modern mht file, and croaked, yielding a panic dump. I´d guess that
the current version of MPlayerX would work.

It was MPlayerX that wanted permission to control my computer, which was
summarily refused.

Turns out the Quicktime had no problem with the mht file, so changed the
mapping so all mht files will go to Quicktime.

As for the mpg file, that did not work: Quicktime complained that it could
not open the file. From what I´ve read, converting to a mp4 file is more
likely to work, because mht is a container for mp4 files.

Joe Gwinn

..

[Jan Panteltje]

On a sunny day (Fri, 23 Aug 2019 06:23:30 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<10d44f71-6254-4695...@googlegroups.com>:

>Hey I found a decent rev. sci. I. article about single phton sources and detectors.
>https://www.dropbox.com/s/1ud9byktcermyvy/single-photon.pdf?dl=0
>(I'm sharing it for educational purposes only.)
>
>I never knew there were so many... and that was from 2011.

Thanks for the paper, am reading it, am at page 6 of 26..
Will take a while.

Yes I have followed some stuff about single photon emission
related to crypto,

I do think those guys make a big mistake there, one article even made me laugh.

From the wave perspective it seems also a joke.
Almost no paper is published these days that does not say 'this will bring the quantum computer a lot closer'.

Same with the ever better battery, but those I do expect to appear for real one day with some real probability.

Your link makes me wonder the same, sure it silly to just look at that single photon case for applications..

If you drop the (wrong) idea that the minimum energy level we can detect is in the form of a single photon,
maybe we can then receive alien transmissions, Alien TV would be interesting.
Right now we are still stuck with (swinging in the direction of politics) a US leader who
declares himself to be 'the chosen one', in my view an other religious fanatic idiot.
https://www.snopes.com/fact-check/trump-second-coming-king-israel/
People seem to follow him like other follow IS and of course he is right (according to those whom he plays).
Wonder when he starts witch burning.
We need indeed better crypto to protect us, but I do not think Photon or Voting ..
will help, better stop here,
I have fun with my PMTs, have 3 now,
More to identify stuff, spectrometry,
AFter I have read your paper I will come back to it, I doubt it will change my ideas though,
Nevertheless it is a nice paper that gives a lot of info o experiments done,

[DecadentLinux...@decadence.org]

Steve Wilson <n...@spam.com> wrote in
news:XnsAAB395001E...@69.16.179.22:

Far out! Best article I've read in a while.

[Robert Baer]

Maybe it crashed your computer because you are running Win10, which
started off in a 80% crash state and deserves to be crashed.

I run WinXP and used the VLC player without batting an eyelash.

[Jasen Betts]

Some sort of H.264 - VLC says

[h264 @ 0x7f24f0012140] Format vaapi_vld chosen by get_format().

H.264 is the compression used by MPEG level 4, but MP4 puts
restrictions on frame size and rate.

file doesn't recognie the file type, so presumably the camera has
tacked on some sort of header

--
When I tried casting out nines I made a hash of it.

[Jan Panteltje]

In the classic follow-up to me myself way,
this is fun too:
https://www.sciencedaily.com/releases/2019/08/190822165018.htm

paper:
https://arxiv.org/abs/1708.00248

This make me wonder if for any event there is a possible observer that can see all possible outcomes.

[DecadentLinux...@decadence.org]

Robert Baer <rober...@localnet.com> wrote in
news:hG18F.83078$9i3....@fx42.iad:

It works fine. It is simply that an 'mts' file is a non-common file
type, and my browser had not made an association for it yet.

Once I pointed it at my player (also VLC) it worked fine.

It looks pretty much to me like you were doing exactly that...
the eyelash batting thing, miss pris.

Somebody said it 'crashed their computer'? I call bullshit.
If someone had a crash playing that file, it was because their
machine is a dogged old POS that can barely play a 320 x 240 much
less real video files.

[DecadentLinux...@decadence.org]

Jan Panteltje <pNaOnSt...@yahoo.com> wrote in
news:qjqmi9$mvs$1...@dont-email.me:

According to Trump, that observer is him.

But we all know he has zero vision in any direction.

[brian]

In message <f4bc94e6-6f1c-492b...@googlegroups.com>,
George Herold <ghe...@teachspin.com> writes

>On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:

>> Well, the MPPC demo system is done. It has four of our small
>> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>> and a box of voltage regulators. Works from single photons up to about
>> 4 mA in one range.
>>
>> This video shows it counting photons, which I still think is a cool
>> thing to be able to do.
>>
>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>

>Not loading here...
>(OK got it.. pretty cool.)
>I've been thinking, reading about photon counting.
>Detector efficiency has to be the number one parameter..
>(well maybe with time resolution.. short spikey pulses.)

To be sure that you've got one photon, you really need about 5 ;-)

Brian
--
Brian Howie

[DecadentLinux...@decadence.org]

jjhu...@gmail.com wrote in
news:cd722eb8-dde8-428c...@googlegroups.com:

Oh, VLC is the best. Also it is really just a front end for
ffmpeg. and ffmplay.

But they ironed out nearly everything one would want to see in
options features and setups.

I had a video that had a very strange aspect ratio and it allows
one to set it up no problem. I had to web hunt to find the solution,
but there it was, and it played great.

[DecadentLinux...@decadence.org]

Jan Panteltje <pNaOnSt...@yahoo.com> wrote in

news:qjm8ke$vcp$1...@dont-email.me:

Your machine must be an old 32 bit Linux box or other such old
crap, and you want new software to run on it.

>
> Use mplayer ffplay, xine.
> mplayer plays it without problems, even a 6 years old version.
> ffmpeg to convert it to someting of normal size.

VLC is merely a front end for ffmplay and ffmpeg, idiot.

> Just imagine poor Joerg downloading that movie
> it would use up a year of his data package.

You are a true idiot. They saw you coming and now they ream your
ass at every chance.

It should be pay and play all month, not pay for each byte. Sounds
like a bunch of greedy bastards over there.

[Sjouke Burry]

Same here,XP SP3 and VLC Media Player 2.0.8 Twoflower

[Robert Baer]

I have some files copied from a security NVR recorder; those files
come in pairs: *.d which is big enough for te video, and *.i which seems
to be like a directory.
The system has a player and an AVI converter; both of which needs to
see the *.i file to work.
Do you have any suggestions of how to get VLC to accept and playtem?

Thanks

[Jasen Betts]

try opening one of the *.d with vlc
if that doesn't work look inside the *.i

[DecadentLinux...@decadence.org]

Robert Baer <rober...@localnet.com> wrote in

news:e0r8F.328488$1b5....@fx37.iad:

the d file is the data and the i file must be the info to play it.
Kind of like a header. Probably proprietarily encrypted.

So contacting them might yield info but they usually blow off folks
wanting access to their files without their hardware. I dunno...
just conjecture.

When one rips a bluray DVD, there is a way to do it that yields
like a 36GB set of files. It is like three files, but it contains
the java and such so that the menus can be played, etc. My PC needs
to be able to run that file at like 10Gb/s to play it though.

Mostly folks make those big files so that any downconversions they
do are done from the best source stock.

But no. I do not really know much about the file types etc. out
there.

My mention about video and Gen Inst. was real video on cable
systems, not captured files and such. And that was a while ago so I
am likely not up on the latest either, though I see what folks use by
simply DLing the files and seeing what they have available.

So I know what h.264 is but knowing what is best, etc. and for what
platforms, etc. Not this kid. I grab what I know works but that is
the extent of it on file types.

[Joseph Gwinn]

On Aug 24, 2019, Sjouke Burry wrote
(in article<5d61eab5$0$26390$e4fe...@textnews.kpn.nl>):

> Same here, XP SP3 and VLC Media Player 2.0.8 Twoflower.

The problems I had were on MacOS, not Windows. See separate posting for
details.

Joe Gwinn

[Robert Baer]

* Did that before my posted query.
On the *.d, VLC search bar showed a tapered, colored bar scanning
back and forth for 20 seconds, and then gave up.

Thanks.
>
>

[Robert Baer]

* Exactly. PITA.

>
> So contacting them might yield info but they usually blow off folks
> wanting access to their files without their hardware. I dunno...
> just conjecture.

* Sent then a query.. Still waiting.

>
> When one rips a bluray DVD, there is a way to do it that yields
> like a 36GB set of files. It is like three files, but it contains
> the java and such so that the menus can be played, etc. My PC needs
> to be able to run that file at like 10Gb/s to play it though.
>
> Mostly folks make those big files so that any downconversions they
> do are done from the best source stock.
>
> But no. I do not really know much about the file types etc. out
> there.
>
> My mention about video and Gen Inst. was real video on cable
> systems, not captured files and such. And that was a while ago so I
> am likely not up on the latest either, though I see what folks use by
> simply DLing the files and seeing what they have available.

* These format(s) are at least 5 years old or so..

>
> So I know what h.264 is but knowing what is best, etc. and for what
> platforms, etc. Not this kid. I grab what I know works but that is
> the extent of it on file types.
>

Thanks.

[Jasen Betts]

That means that vlc looked all through the file and didn't find anything
that it recognised as video. I'm not sure how to proceed.

[George Herold]

Grin. I have seen reports of single photon detection eff of ~75%.

George H.
>
> Brian
> --
> Brian Howie

[Phil Hobbs]

You can crank up the bias to improve the detection efficiency, but the
false count rate goes through the roof.

[Robert Baer]

Thanks.

[Dimiter_Popoff]

On 8/22/2019 18:06, Phil Hobbs wrote:

> On 8/22/19 10:08 AM, jjhu...@gmail.com wrote:
>> On Wednesday, August 21, 2019 at 6:19:01 PM UTC-4, Phil Hobbs wrote:
>>> Well, the MPPC demo system is done.  It has four of our small
>>> proprietary boards (controller/SMPS, TEC driver, voltage-controlled
>>> amplifier, and APD bias) plus a handwired pHEMT-boostrapped front end
>>> and a box of voltage regulators.  Works from single photons up to about
>>> 4 mA in one range.
>>>
>>> This video shows it counting photons, which I still think is a cool
>>> thing to be able to do.
>>>
>>> <https://electrooptical.net/www/sed/MPPCphotonCounting.mts>
>>>

>>> Cheers
>>>
>>> Phil Hobbs
>>>
>>> --
>>> Dr Philip C D Hobbs
>>> Principal Consultant
>>> ElectroOptical Innovations LLC / Hobbs ElectroOptics
>>> Optics, Electro-optics, Photonics, Analog Electronics
>>> Briarcliff Manor NY 10510
>>>
>>> http://electrooptical.net
>>> http://hobbs-eo.com
>>

>> Please excuse this naive question as this is not my background, but....
>> What kind of detector is being used?
>
> It's a Hamamatsu S13362-3050.  The product will use a tiled array.
>
> how do you know if you missed a photon? have two or more coincident
> ones? or miscounted? e.g. false positives and false negatives.
>
> You miss most of the photons.  The probability of detection is only
> about 40% at most, and only 74% of the area is active.  It's roughly
> competitive with a PMT.
>
>> If my recollection from college physics is correct, a photon has a
>> certain energy level.  Do all photons have the same energy level or do
>> they vary?
>
> They vary.  Energy is hc/lambda.
>
>> I would imagine if they can contain different energy levels then
>> discriminating >between n>1 hits would be very tricky.

>
> The pulse height doesn't depend on the photon energy.
>

That is surprising, semiconductor gamma-ray detectors (e.g. HPGe) have
the best energy resolution to date. Obviously this being a small device
its energy range would not go high enough so there is likely no
practical application for that.

On a side note, what throughput did you manage? (counts/second after
which the counts which make it through start to decline).
I recently did photon counting using a good old PMT (well not old
really, a fairly new Hamamatsu model), easily got > 20M cps which was
plenty for the application (a TLD reader, yet to be announced, don't
look for it yet on the website, perhaps next week :).

Dimiter

======================================================
Dimiter Popoff, TGI http://www.tgi-sci.com
======================================================
http://www.flickr.com/photos/didi_tgi/

[George Herold]

For some of the SPAD's one photon causes the whole capacitance
to discharge (by the over-voltage)... another photon before it
recharges is likely missed.

George H.

[Dimiter_Popoff]

They all have a certain dead time, given that the events are stochastic
this will always happen, how often will depend on the input count rate
and on the amount of dead time (which is mostly produced by the
electronics after the detector, the one the detector produces is
typically negligible but it is there allrigh. Reporting the correct
overall dead time is an integral part of a measured gamma spectrum
and it is non-trivial, a competitor call that "zero dead time", we
do it by DSP software and call it nothing, just "dead time" as it is
certainly not zero as their name implies (their results are also
correct, just not zero, more or less the same as ours)).

However this has little to do with energy resolution, the pulse height
depends on the number of electrons the photon has managed to kick
into the detector which is proportional to the photon energy. In fact
HPGe (and Si) detectors are *very* linear.

[George Herold]

OK, I don't know about gamma's... but I can imagine you can get
multiple electrons.
For visible stuff with Si photodiodes in the linear range one photon =
one electron. When run in the avalanche region, you get a X-electrons
per photon... where X is the gain, and is stochastic. And then run
in the geiger-mode (Spads), a photon discharges the whole diode capacitance,
and you get pulses that are all basically the same height.
(The only time the pulses are shorter (in amplitude) is when you get a photon
triggering the spad, while it's still recharging from the previous event.
And finally there are these MPPC things that Phil is using. I've never used
one of those.. but IIUI you have an array of spads, and then can again have
different peak heights if there is more than one photon... you can see some
of those double pulses in Phil's video.

George H.

[pcdh...@gmail.com]

>For some of the SPAD's one photon causes the whole capacitance
>to discharge (by the over-voltage)... another photon before it
>recharges is likely missed

That's not a huge issue with these ones, at least not in analogue mode. Their pixels are only 50 um square, so they have lots (3400-odd iirc) and they recharge again in about 20 ns. Each one dumps about 2 million electrons, so the saturation current is about 55 mA. At 53 V bias, the poor thing would be dissipating almost three watts, which would turn it to lava.

Cheers

Phil Hobbs

[George Herold]

And ruin your day. :^) I assume you have some current limit in the supply line
that will stop that from happening... when some tech open's the unit up to room light.

GH
>
> Cheers
>
> Phil Hobbs

[Dimiter_Popoff]

I get it, in fact it is obvious there would be no energy resolution to
speak of. The energy range for visible light is below 2eV, the best HPGe
detectors have a resolution of hundreds of eV at low (122keV, 59.5keV)
and some xray Si detectors go down to around 100 eV resolution. I just
did not think of how narrow an energy range we were talking about :-).

Dimiter

[Jan Panteltje]

On a sunny day (Tue, 27 Aug 2019 06:23:42 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<aac65532-5337-4f6c...@googlegroups.com>:

Years agao I looked for SPADs and got 'we do not sell this to your country' crap.

After reading some of this here, I decided to look on ebey if they EXIST[1] now.

No S.P.A.D
No single photon avalanche detector,
but looked at some other entries,
this caucht my attention, surprized:
https://www.ebay.com/itm/262592051982
VL53L0X World smallest Time-of-Flight (ToF) ranging sensor NEW
I though maybe of use for my drone's anti collision system, so started reading the desciption:
....
The VL53L0X integrates a leading-edge SPAD array (Single Photon Avalanche Diodes) and embeds ST\u2019s second generation FlightSenseTM patented technology.
The VL53L0X's 940nm VCSEL emitter (Vertical Cavity Surface-Emitting Laser), is totally invisible to the human eye, coupled with internal physical infrared filters, it enables longer ranging distance, higher immunity to ambient light and better robustness to cover-glass optical cross-talk.
Key Features
Fully integrated miniature module
940nm Laser VCSEL
VCSEL driver
....

LOL, and there is the SPAD
Any comments?
I have ordered one just now :-) 8$26 with free shipping.
??
There is even an arduino library
https://github.com/ScruffR/VL53L0X


[1] Not on ebay means does not exist.

[Phil Hobbs]

The physics is completely different. Ge(Li) and IG detectors get their
high resolution from the primary particle producing N carriers, where N
is proportional to its energy.

MPPCs are avalanche devices, where a detection event causes the whole
pixel to discharge until the avalanche stops.

>
> On a side note, what throughput did you manage? (counts/second after
> which the counts which make it through start to decline).
> I recently did photon counting using a good old PMT (well not old
> really, a fairly new Hamamatsu model), easily got > 20M cps which was
> plenty for the application (a TLD reader, yet to be announced, don't
> look for it yet on the website, perhaps next week :).

Because of the highish capacitance, the output pulses aren't as
symmetrical as a PMT's--the fall time is about 20x longer than the rise.
So to get PMTish photon counting rates you need a more intelligent
discriminator circuit that can reliably see events that arrive on the
tails of other events.

Cheers

Phil Hobbs

(coming to you from beautiful Sydney BC waterfront)

[Phil Hobbs]

> opens the unit up to room light.

Yup, a couple of parallelled LND150s inside the voltage feedback loop.

There's also an I2C pressure sensor to detect the chamber venting, so
that we can turn off the bias and warm the device back up to 20C before
we get ice all over it.