A 1.00 mW laser produces photons of wavelength 633 nm. How many photons per second does the laser emit?

Question

Quizplus · Accepted Answer

The energy of a single photon can be calculated using E = hc/λ, where h is Planck's constant (6.626 × 10^-34 J·s), c is the speed of light (3.00 × 10^8 m/s), and λ is the wavelength (633 nm = 633 × 10^-9 m). The power of the laser is 1.00 mW = 1.00 × 10^-3 J/s. The number of photons per second is the power divided by the energy per photon. This calculation results in approximately 3.19 × 10^15 photons per second.

A 100 MW Laser Produces Photons of Wavelength 633 Nm