- #1

- 4

- 3

- Homework Statement
- How are we to calculate the attenuation necessary to reduce the number of photons emitted from a laser beam to one photon per meter?

- Relevant Equations
- N = Plambda/hc(^2)

where N = photons per meter, P = power of beam, lambda = wave length, h = planck's constant, c = speed of light

E = hc/lambda

where E = energy of single photon

Hi there. I am attempting to do calculations for my own project, the question being what is the attenuation necessary to reduce the number of photons in a beam to single-photon levels. N approximately 1 or 2.

The laser in question is a 650nm 5mW laser.

I have solved the energy per photon 3.06*10(^-19) J.

I have solved the number of photons emitted from the laser beam per second 1.63*10(^16) photons of light per second.

I am struggling to find the photons per meter. I may have got the previous calculations wrong as well.

My calculations suggest 5.44662309×10(^12). A small part of me wants to be this wrong as this is if I am right entailing the need for the laser to be attenuated by 10x(^-12) so 12 orders of magnitude. If that is right of course.

I am very appreciative of any and all help. I've probably got this all wrong lol.

Thanks

The laser in question is a 650nm 5mW laser.

I have solved the energy per photon 3.06*10(^-19) J.

I have solved the number of photons emitted from the laser beam per second 1.63*10(^16) photons of light per second.

I am struggling to find the photons per meter. I may have got the previous calculations wrong as well.

My calculations suggest 5.44662309×10(^12). A small part of me wants to be this wrong as this is if I am right entailing the need for the laser to be attenuated by 10x(^-12) so 12 orders of magnitude. If that is right of course.

I am very appreciative of any and all help. I've probably got this all wrong lol.

Thanks