A helium-neon laser emits light at 632.8 nm.If the laser emits $1.82 \times 10^{17} $ photons/second,what is its power output in mW? (c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s)

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Quizplus · Accepted Answer

The energy of a single photon is given by:$$E = hf = \frac{hc}{\lambda}$$where:* $h$ is Planck's constant* $f$ is the frequency of the light* $c$ is the speed of light* $\lambda$ is the wavelength of the lightThe power output of the laser is given by:$$P = N \times E$$where:* $N$ is the number of photons emitted per second* $E$ is the energy of a single photonSubstituting the given values into the equations above, we get:$$E = \frac{(6.626 \times 10^{-34} \text{ J} \cdot \text{s})(3.00 \times 10^8 \text{ m/s})}{632.8 \times 10^{-9} \text{ m}} = 3.14 \times 10^{-19} \text{ J}$$$$P = (1.82 \times 10^{17} \text{ photons/s})(3.14 \times 10^{-19} \text{ J/photon}) = 57.2 \text{ mW}$$Therefore, the power output of the laser is 57.2 mW.

A Helium-Neon Laser Emits Light at 632 1.82×10171.82 \times 10^{17} 1.82×1017

A Helium-Neon Laser Emits Light at 632 $1.82 \times 10^{17}$