Відео

So it would seem

@@krifakhalil1286 Nah what?

As I exist as physical being, a non-physical in reality, I appreciate how your conscious mind engaged with and responded to the information provided by the speaker-a concrete study, indeed. In another dimension, we might meet. A salute and tribute to you and the master of the video.

Probably as these LEDs are actually very bad SPAD sensors with poor quantum efficiency and too much capacitance for those kinds of speed. We just use them as an instructional tool! For a 30ns pulse width you're going to need a professional SPAD detector with small active area and a reasonably fast oscilloscope. Maybe check out the APD430A from Thor, believe it or not, these have actually gotten cheaper over the years!

Dudes, these LEDs are chosen specifically for their very poor quantum efficiency. Indeed, if you blasted a "real" SPAD with ambient light it would fry. This setup is just a low-consequence teaching tool...

@@jonathannewport8557 Why are you repeating, again, that you are clueless about physics? I don't care. Do you know what one photon per second looks like experimentally? It's a windowless room inside a building with the lights off and three layers of blackout curtains on the door. Inside that room is a light tight box. Inside that box is another light tight box. Then you wait for 24 hours for all luminescence in the materials in these boxes to dissipate. THAT is one photon per second. If you are lucky. ;-)

lots of light and a short exposure time!

Woohoo! a comment from The Creator! I have not tried the dynamic particle model. I recorded videos and this tutorial for my lab students years ago and this seems to be getting some tracktion [sic] during COVID. I should probably post these videos somewhere for public consumption, but always felt they could have been done better by someone with a global shutter camera and some proper lighting...

When the diode is in darkness, the count rate is very low (can be single digit), meaning that photons are triggering such events. The following is from Wikipedia: Avalanche photodiodes (APDs) are not single photon detectors. The experiment uses a single photon avalanche photodiode (SPAD). APDs are biased close to, but not exceeding the breakdown voltage of the semiconductor. This high electric field provides an internal multiplication gain only of the order of few hundreds, since the avalanche process is not diverging (also known as run-away avalanche) as in the case of SPAD avalanche discharges. The resulting avalanche current intensity is linearly related to the optical signal intensity. A SPAD, however, operates with a bias voltage above the breakdown voltage. Because the device is operating in this unstable above-breakdown regime, a single photon (or a single dark-current electron) can set off a significant avalanche of carriers. Practically, this means that in an APD, a single photon produces only tens or few hundreds of electrons, but in a SPAD a single photon triggers a current in the milliampere region (billions of billions of electrons per second) that can be easily "counted". Therefore, while the APD is a linear amplifier for the input optical signal with limited gain, the SPAD is a trigger device, and this triggering is what we are seeing in the experiment.

He's just using an ordinary LED and carefully adjusting the reverse bias voltage to a point just below where the LED breaks down (non-destructive avalanche breakdown). At this point, even just a single photon can put the LED over the edge and into breakdown. The circuit is feeding the LED through a resistor so when the LED breaks down, the voltage drops because the current rises and the resistor voltage drop increases. This takes the LED out of avalanche and the voltage rises back to the preset level, ready for another photon to arrive. There are special photon-counting avalanche photodiodes which have much higher performance - the main differences are that they have a much more stable avalanche threshold so you don't have to keep tuning it to stay right below breakdown. They also react to a higher fraction of photons which enter the diode (the LED might only react to 5 or 10% of them).

The AND113R diodes are used for such projects. They are not specialized but have the avalanche property very prominent.

​@@sbrehenywhere can I buy a specialized SPAD diode?

@@mix_dev6959 did you try to google? thorlabs, hamamatsu for example if you need lab grate.

2sc5707 кт315 ua-cam.com/video/Ju1UIuoVvCo/v-deo.html

+James Reegan This display indeed uses the OctoWS2811 Library. Look at the code in the link provided below the video. Also, it is easy to switch to a mic input on the Audio Adapter board, just do this in the code: //const int myInput = AUDIO_INPUT_LINEIN; const int myInput = AUDIO_INPUT_MIC;

+Jonathan Newport awesome, now I just gotta figure out how in the world to fit all that in my daft punk helmet and control it wirelessly. Lol wonder if TouchOSC would have the functionality for that.

I'd like to be able to switch between this and set visuals all for a display in a Daft Punk Helmet, not sure if it can be easily switched between

Super late but this would be extremely easy. In fact easier than what he is doing. Microphone would only have to check the differences between noise level rather than audio spectrum analysis.

+Ul Tra This isn't available for purchase, but you can build your own! I just posted some links in the description to the printed circuit boards on OSHPark and to the code I used to program the teensy for this particular application.