Q- Lasers can be used to drill or cut material. One such laser generates a series of high-intensity pulses rather than a continuous beam of light. Each pulse contains 420 mJ of energy and lasts 10 ns. The laser fires 10 such pulses per second.

(a) What is the peak power of the laser light? The peak power is the power output during one of the 10 ns pulses. 

(b) What is the average power output of the laser? 

(c) A lens focuses the laser beam to a 8 µm diameter circle on the target. During a pulse, what is the average light intensity on the target? 

(d) The intensity of sunlight at midday is about 1100 W/m². What is the ratio of the laser intensity on the target to the intensity of the midday sun? 

Solution: