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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 15 ns and contains 1.0 mJ of light energy.

– How powerful is a single laser pulse? – What’s the strength of a light wave during the incredibly brief pulse? The main objective of this question is to find how powerful is a single laser pulse and strength of a light wave. This question uses the concept of peak power. Peak power is the term used to describe the highest optical power that a laser pulse may produce. It is a measure of the energy content of a laser pulse relative to its temporal time, or pulse width, in more general terms.

Expert Answer

a) First we have to calculate the how powerful is a single laser pulse. The amount of energy released in relation to the amount of time it was released will determine the power. So: \[ \space  P \space = \space \frac{E}{t} \] By putting the values, we get: \[ \space = \space \frac{1 \space . \space 10^-3} {1.5 \space . \space 10 ^-8} \] \[ \space = \space \frac{0.66 \space . \space 10^-3}{10^-8} \] \[ \space = \space 0.66 \space . \space 10^5 \] \[ \space = \space 66666.66 \] \[ \space = \space 66.7 \space kW  \] b) Now we have to find the strength of light wave. So: \[\space I \space = \space \frac{E}{t} \] \[\space = \space \frac{4P}{\pi d^2} \] By putting values, we get: \[\space = \space \frac{4 \space . \space 66700}{\pi \space . \space 0.001^2} \] \[\space = \space 8.5 \space . \space 10^{10} \space \frac{W}{m^2} \]

Numerical Answer

The power of a single laser pulse is: \[ \space = \space 66.7 \space kW  \] The strength of the light wave during the incredibly brief pulse is: \[\space = \space 8.5 \space . \space 10^{10} \space \frac{W}{m^2} \]

Example

Laser light pulses are used during LASIK eye surgery to reshape the cornea by shaving off tissue. A common LASIK laser produces a $ 193  nm $ laser beam that is $ 2.0 mm  $ in diameter $ . 15 ns $  and $ 1.0 mj $ of visible light are contained in each laser pulse. How powerful is a single laser pulse? What’s the strength of a light wave during the incredibly brief pulse? First, we have to calculate how powerful is a single laser pulse. The amount of energy released in relation to the amount of time it was released will determine the power. So: \[ \space  P \space = \space \frac{E}{t} \] By putting the values, we get: \[ \space = \space \frac{2 \space . \space 10^-3} {1.5 \space . \space 10 ^-8} \] \[ \space = \space \frac{1.333 \space . \space 10^-3}{10^-8} \] \[ \space = \space 1.333 \space . \space 10^5 \] \[ \space = \space 133333.33 \] \[ \space = \space 133333.33\space W  \] Now we have to find the strength of the light wave. So: \[\space I \space = \space \frac{E}{t} \] \[\space = \space \frac{4P}{\pi d^2} \] By putting values, we get: \[\space = \space \frac{4 \space . \space 133333.33}{\pi \space . \space 0.002^2} \] \[\space = \space 4.24 \space . \space 10^{10} \space \frac{W}{m^2} \] The power of a single laser pulse is: \[ \space = \space 133333.33\space W  \] The strength of the light wave during the incredibly brief pulse is: \[\space = \space 4.24 \space . \space 10^{10} \space \frac{W}{m^2} \]
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