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. a) 511 W b) 845 W c) 700 W d) 667 W e) 1040 W

Answer 1

b) 845 W

Step-by-step explanation:

Diameter = 1 mm

E = Electric field = 0.9 MV/m

Average power = Intensity (I) × Area (A)

Intensity

I = 0.5ε₀E²c

ε₀ = 8.85×10⁻¹² F/m

c = 3×10⁸ m/s

I = 0.5 × 8.85×10⁻¹² × (0.9×10⁶)²× 3×10⁸

Area

A = πr² = π0.5²×10⁻⁶

Average power = 0.5 × 8.85×10⁻¹² × (0.9×10⁶)²× 3×10⁸× π0.5²×10⁻⁶ = 844.5190

Average power of the laser is 845 W