LASIK eye surgery uses pulses of laser light to shave off tissue from the cornea
ID: 1347580 • Letter: L
Question
LASIK eye surgery uses pulses of laser light to shave off tissue from the cornea, reshaping it. A typical LASIK laser emits a 1.0-mm-diameter laser beam with a wavelength of 193 nm. Each laser pulse lasts 19 ns and contains 2.0 mJ of light energy. What is the power of one laser pulse? Express your answer to two significant figures and include the appropriate units. During the very brief time of the pulse, what is the intensity of the light wave? Express your answer to two significant figures and include the appropriate units.Explanation / Answer
Now, Power of a pulse is the energy it carries/ the lifetime of a pulse
Power = 2.0mJ/(16ns) = 2*10^-3 / (16*10^-9) = 1.25 * 10 ^5 W = 125 kW
Intensity = Power / area of the pulse
area of pulse = Pi * r^2 = Pi* (1mm/2)^2 = Pi * (10^-3/2)^2 = 7.85 * 10^-7 m^2
Intensity = 125 * 10^3 / (7.85 * 10^-7) = 15.92 * 10^10 W/m^2
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