Counting photons with an MPPC

Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in
news:qjm8ke$vcp$1@dont-email.me:

On a sunny day (Thu, 22 Aug 2019 06:50:58 -0700 (PDT)) it happened
jjhudak4@gmail.com wrote in
0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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.

 

jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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

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.

 

[Sjouke Burry]

On 24.08.19 5:53, Robert Baer wrote:

Joseph Gwinn wrote:
On Aug 21, 2019, Phil Hobbs wrote
(in article <qjkg0h$cl8$1@dont-email.me&gt:

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

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.

Same here,XP SP3 and VLC Media Player 2.0.8 Twoflower

 

[Robert Baer]

DecadentLinuxUserNumeroUno@decadence.org wrote:

jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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]

On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:

DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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

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


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

 

Robert Baer <robertbaer@localnet.com> wrote in
news:e0r8F.328488$1b5.38649@fx37.iad:

DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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

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$26390$e4fe514c@textnews.kpn.nl&gt:

On 24.08.19 5:53, Robert Baer wrote:
Joseph Gwinn wrote:
On Aug 21, 2019, Phil Hobbs wrote
(in article <qjkg0h$cl8$1@dont-email.me&gt:

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
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.
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]

DecadentLinuxUserNumeroUno@decadence.org wrote:

Robert Baer <robertbaer@localnet.com> wrote in
news:e0r8F.328488$1b5.38649@fx37.iad:

DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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


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.
* 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.

 

[Robert Baer]

Jasen Betts wrote:

On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:
DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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

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

* 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.

 

[Jasen Betts]

On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:

Jasen Betts wrote:
On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:
DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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

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

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.

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

 

[George Herold]

On Saturday, August 24, 2019 at 9:47:19 AM UTC-4, brian wrote:

In message <f4bc94e6-6f1c-492b-ac39-ebba09198693@googlegroups.com>,
George Herold <gherold@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 ;-)
Grin. I have seen reports of single photon detection eff of ~75%.

George H.

Brian
--
Brian Howie

 

[Phil Hobbs]

On 8/26/19 9:31 AM, George Herold wrote:

On Saturday, August 24, 2019 at 9:47:19 AM UTC-4, brian wrote:
In message <f4bc94e6-6f1c-492b-ac39-ebba09198693@googlegroups.com>,
George Herold <gherold@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 ;-)
Grin. I have seen reports of single photon detection eff of ~75%.

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

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

 

[Robert Baer]

Jasen Betts wrote:

On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:
Jasen Betts wrote:
On 2019-08-25, Robert Baer <robertbaer@localnet.com> wrote:
DecadentLinuxUserNumeroUno@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:cd722eb8-dde8-428c-955e-fdb0e44e6e50@googlegroups.com:

On Thursday, August 22, 2019 at 10:01:02 AM UTC-4,
DecadentLinux...@decadence.org wrote:
jjhudak4@gmail.com wrote in
news:0490f492-9c27-4f56-ae10-6da9a3aa3aca@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.

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


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.

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

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

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.

Thanks.

 

[Dimiter_Popoff]

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

On 8/22/19 10:08 AM, jjhudak4@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]

On Monday, August 26, 2019 at 6:57:59 PM UTC-4, dp wrote:

On 8/22/2019 18:06, Phil Hobbs wrote:
On 8/22/19 10:08 AM, jjhudak4@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.

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.

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/

 

[Dimiter_Popoff]

On 8/27/2019 3:31, George Herold wrote:

On Monday, August 26, 2019 at 6:57:59 PM UTC-4, dp wrote:
On 8/22/2019 18:06, Phil Hobbs wrote:
On 8/22/19 10:08 AM, jjhudak4@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.

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.

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.

Dimiter

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

 

[George Herold]

On Tuesday, August 27, 2019 at 8:47:13 AM UTC-4, dp wrote:

On 8/27/2019 3:31, George Herold wrote:
On Monday, August 26, 2019 at 6:57:59 PM UTC-4, dp wrote:
On 8/22/2019 18:06, Phil Hobbs wrote:
On 8/22/19 10:08 AM, jjhudak4@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.

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.

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.

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.

Dimiter

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

 

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]

On Tuesday, August 27, 2019 at 9:12:49 AM UTC-4, pcdh...@gmail.com wrote:

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.

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]

On 8/27/2019 16:07, George Herold wrote:

On Tuesday, August 27, 2019 at 8:47:13 AM UTC-4, dp wrote:
On 8/27/2019 3:31, George Herold wrote:
On Monday, August 26, 2019 at 6:57:59 PM UTC-4, dp wrote:
On 8/22/2019 18:06, Phil Hobbs wrote:
On 8/22/19 10:08 AM, jjhudak4@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.

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.

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.

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.

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