Question

. High power laser has a beam diameter of 1 mm and generates an electric field with an amplitude of 0.9 MV/m at the target. Find the average power of the laser. e) 1040 W d) 667 W c) 700 W b)845 W a) 511 W

Answer 1

Average power, P = 845 watts

Step-by-step explanation:

It is given that,

High power laser has a beam diameter of 1 mm, d = 1 mm

Radius, r = 0.0005 m

Electric field,
`E=0.9\ MV/m=0.9* 10^6\ V/m`

Average power of the laser is given by :

`P=I* A`

Where

I is the intensity,
`I=(1)/(2)\epsilon_oE^2c`

This gives,
`P=(1)/(2)\epsilon_oE^2c * \pi r^2`

`P=(1)/(2)\pi r^2\epsilon_oE^2c`

`P=(1)/(2)\pi * (0.0005)^2* 8.85* 10^(-12)* (0.9* 10^6)^2* 3* 10^8`

P = 844.51 watts

or

P = 845 watts

So, the average power of the laser is 845 watts. Hence, this is the required solution.