Question

A laser emits photons continuously at a rate of 6.4*1016/s. If the wavelength of the photons is 453 nm, what is the laser power in mW?

Answer 1

To calculate the laser power in mW, convert the given wavelength to meters, calculate the energy of each photon using Planck's constant and the speed of light, and then multiply the number of photons emitted per second by the energy. Finally, simplify the expression to find the laser power in mW.

Step-by-step explanation:

To calculate the laser power in milliwatts, we need to convert the given wavelength to meters and use the formula:

Power = Energy/time = (number of photons emitted per second) * (energy of each photon)

First, let's convert the wavelength to meters:

Wavelength = 453 nm = 453 * 10^(-9) m

Next, we can calculate the energy of each photon using the formula:

E = hf = hc/λ

where h is Planck's constant = 6.63 * 10^(-34) J·s and c is the speed of light = 3.00 * 10^8 m/s.

Now, we can calculate the power:

Power = (6.4 * 10^(16) photons/s) * (E)

Substituting the values, we get:

Power = (6.4 * 10^(16) photons/s) * [(6.63 * 10^(-34) J·s)(3.00 * 10^8 m/s)/(453 * 10^(-9) m)]

Simplifying the expression gives us the laser power in mW.