Question

A certain laser outputs pure red light (photon energy 1.8 eV) with power 550 milliwatts (0.55 watts). How many photons per second does this laser emit

Answer 1

We want to find how many photons per second a laser emits given that we know the energy of a single photon and the power of the laser, we will get:

1.90712*10^18 photons per second.

So we know that the photon energy is 1.8 eV, and the laser power is:

P = 0.55 watts

Remember that:

1 watt = 1 J/s

And:

1 eV = 1.60218*10^(-19) J

Then we can convert the two values that we have so we have both in joules:

Power = P = 0.55 J/s

Energy = 1.8 eV = 1.8*(1.60218*10^(-19) J) = 2.883924*10^(-19) J

The number of photons emitted per second is just the quotient between the power and the energy of a single photon, we have:

Number = (0.55 J/s)/(2.883924*10^(-19) J) = 1.90712*10^18 photons per second.

If you want to learn more, you can read:

brainly.com/question/20343793