A red laser with a wavelength of 670 nmnm and a blue laser with a wavelength of 470 nmnm emit laser beams with the same light power. How do their rates of photon emission compare

red laser emits 1.42 times the number of photons of the blue laser, per unit of time

Explanation:

In order to calculate the rates of photon emission for both wavelengths, you take into account that the power of the light is given by the following formula:

       (1)

That is, the power is the energy per time.

h: Planck's constant

c: speed of light

λ: wavelength of the light

The number of photons emitted per unit of time is given by:

P: power of the light

E: energy of the light

For the two wavelengths you have

  (2)

Where you have use that P1=P2

Finally, you replace the values of the wavelengths in the equation (2):

Then, the red laser emits 1.42 times the number of photons emited by the blue laser

if they have a finite resultant