![A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW](https://www.gkseries.com/blog/wp-content/uploads/2023/08/A-pulsed-laser-emits-rectangular-pulses-of-width-1-nanosecond-at-a-repetition-rate-of-1-kHz.-If-the-average-power-output-is-1-mW-1.jpg)
Q. A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW, the average power over a single pulse duration, in watts, is
(A) 1 (B) 10 (C) 100 (D) 1000
Ans: 1000
Sol:
The underlying concept here to be used is that the energy is not a function of time
Hence, Eavg = Epeak
Calculations
Pwidth = 1 nano sec,
Pulse laser frequency = T = 1/f = 1 msec
Energy of laser pulse width=E/T
![](https://www.gkseries.com/blog/wp-content/uploads/2023/08/Screenshot-622.png)