Final review: Photons per second

[Ari Summers 3H]

Realized I’ve forgotten how to calculate power, given photons per second and wavelength. Anyone have a quick review pointer on this?

[William Sahney Lec 3 Dis 3l]

Find the energy per photon using the wavelength:

E= hc/λ
​
Multiply the energy per photon by the number of photons per second to get the total power:
Power = E × Number of photons per second

This will give you the power of the light in watts (Joules per second).

[Azlyn Hernandez 2E]

And to add on, the units of energy should be in Joules, Power is in watts (or joules per second). It is also important that wavelength is in meters, so if they are given as nanometers you can use the conversion factor: 1nm = 10^(-9)m.