A laser used for many applications of hard surface dental work emits 2780-nm wavelength pulses of variable energy (0-300 mJ) about 20 times per second. part a. Determine the number of photons in one 80-mJ pulse. part b. Determine the average power of photons in one 80-mJ pulse during 1 s.

a

b

Explanation:

From the question we are told that

    The wavelength is  

     The  energy  is  

This energy is mathematically represented as

Where  c is the speed of light with a value  

             h is the Planck's  constant with the value  

             n is the number of pulses

So

substituting values

Given that the pulses where emitted 20 times in one second then the period of the pulse is

Hence the average power of photons in one 80-mJ pulse during 1 s is mathematically represented as

substituting values

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