Optical Noise Photons: Calculate Sun's Ambient Light for Detector Simulation

In summary, a photon detector registers a number of photons per second depending on the bandwidth and quantum efficiency of the detector.
  • #1
Xyius
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I need this information for a simulation I am working on that involves optical photon detectors.

Specifically, I need a rough figure for how many photons a photon detector would register per second if I were to place it in ambient light from the sun.

I realize that this number depends on the bandwidth of the detector and its quantum efficiency at different wavelengths, but let's assume I have tight bandwidth in the green part of the spectrum (say less than 100nm) with a very sharp roll off.

Would the detector saturate? Or is the amount of ambient photons low enough to register a good number?

I'm thinking I may be able to calculate a rough number based on how much radiation the sun shines on the Earth over the bandwidth I need. I probably will try this later, but I figured I would ask to get a number I can compare with.
 
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  • #2
There are some subtle issues here.:

http://www.optics.rochester.edu/assets/grad_research_interest/Quantum%20Optics.pdf
http://www.uni-saarland.de/fileadmin/user_upload/Professoren/fr72_ProfBushev/Zusatzmaterial/Statistical_Optics.pdf

Temporally coherent light (laser light) is classical: photons are emitted at random, and so the intensity obeys Poisson statistics for photon number. Thermal light is "chaotic" and obeys different statistics.

Does this help?
 
  • #3
What exactly is "ambient" light from the Sun?
 
  • #4
Andy Resnick said:
There are some subtle issues here.:

http://www.optics.rochester.edu/assets/grad_research_interest/Quantum%20Optics.pdf
http://www.uni-saarland.de/fileadmin/user_upload/Professoren/fr72_ProfBushev/Zusatzmaterial/Statistical_Optics.pdf

Temporally coherent light (laser light) is classical: photons are emitted at random, and so the intensity obeys Poisson statistics for photon number. Thermal light is "chaotic" and obeys different statistics.

Does this help?
Thank you for your reply. These links will definitely be useful when I do a theoretical analysis.

What I was hoping for is an experimenter that has access to photon counter that can tell me what it registers when it is out in normal lighting conditions outside. Does the detector saturate?
Drakkith said:
What exactly is "ambient" light from the Sun?
Light from the sun on Earth. As in, bring the detector outside.Sorry if this is kind of a weird question, I just need a general figure of how many "noise photons per second" I should expect from outdoor lighting conditions, say on a sunny day.
 
  • #5
Xyius said:
Light from the sun on Earth. As in, bring the detector outside.

Okay, but there's a big, big difference between having the detector in direct sunlight or having it under a shady overhang. Both are outside, but direct sunlight will probably saturate your sensor in less than a second depending on what kind of sensor you have.
 
  • #6
Call me an experimentalist, but why not just measure it?
 
  • #7
e.bar.goum said:
Call me an experimentalist, but why not just measure it?

Hush! Experimentalists aren't allowed to speak! Now back to the closet with you!
 
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  • #8
Drakkith said:
there's a big, big difference between having the detector in direct sunlight or having it under a shady overhang
Not to mention what's going on in the atmosphere. Green is the most effective "carrier" colour under water, but less so in air. So, even just in that tiny regard, cloud cover and humidity would affect how much green gets to your detector.
 
  • #9
Xyius said:
Thank you for your reply. These links will definitely be useful when I do a theoretical analysis.

What I was hoping for is an experimenter that has access to photon counter that can tell me what it registers when it is out in normal lighting conditions outside. Does the detector saturate?Light from the sun on Earth. As in, bring the detector outside.Sorry if this is kind of a weird question, I just need a general figure of how many "noise photons per second" I should expect from outdoor lighting conditions, say on a sunny day.
PVlighthouse's spectrum library has a calculator for finding the photon flux for a given wavelength range. From that it's simple to find the number of photons.
 
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  • #10
Vagn said:
a calculator for finding the photon flux for a given wavelength range
Bookmarked. Thanks for that.
 
  • #11
Xyius said:
Thank you for your reply. These links will definitely be useful when I do a theoretical analysis.

What I was hoping for is an experimenter that has access to photon counter that can tell me what it registers when it is out in normal lighting conditions outside. Does the detector saturate?

No sane owner of a photon counter is going to take it outside and use it during the day.
 
  • #12
Vagn said:
PVlighthouse's spectrum library has a calculator for finding the photon flux for a given wavelength range. From that it's simple to find the number of photons.

Thank you! This is what I need!

e.bar.goum said:
Call me an experimentalist, but why not just measure it?

Haha. Well at the moment, I do not have access to any equipment.

Thanks for all the replies!
 
  • #13
Look up insolation. You should be able to find average solar power near where you live. You can assume that the spectrum is fairly close to a black body during mid-day. (If you need more than a rough estimate, you'll have to factor in scattering effects on the spectrum, but then you'd be better off just measuring the thing.) From the insolation and the spectrum, you can calculate the photon flux. Of course, you need to adjust based on the angle of your detector to the sun (simply cos(theta)).
Integrate the photon flux * the quantum efficiency of your detector to get the counts/second. Good CCDs have quantum efficiencies > 80%. Compare that count to the well depth of your detector or your ADC max counts.
 

1. What is optical noise in the context of photon detection?

Optical noise refers to the random fluctuations of photons in a detection system that can interfere with the accuracy of measurements. It can originate from external sources such as ambient light or internal sources such as electronic noise.

2. How is the amount of ambient light from the sun calculated for detector simulation?

The amount of ambient light from the sun can be calculated by using the solar irradiance values for the location and time of the simulation, and the distance between the sun and the detector. These factors can be used to determine the number of photons that reach the detector at a given time.

3. What is the impact of optical noise on detector performance?

Optical noise can significantly affect the performance of a detector by introducing errors or reducing the sensitivity of the system. It can also make it difficult to distinguish the signal from the background noise, leading to false readings or decreased accuracy.

4. How can optical noise be reduced in photon detection systems?

There are several methods for reducing optical noise in photon detection systems. These include using filters to block out unwanted light, using shielding to prevent external interference, and optimizing the design of the detector to minimize internal noise sources.

5. Are there any techniques for mitigating the effects of optical noise in detector simulations?

Yes, there are various techniques that can be used to mitigate the effects of optical noise in detector simulations. These include increasing the integration time of the simulation, using advanced algorithms to filter out noise, and incorporating noise models into the simulation to more accurately represent real-world conditions.

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