The red light emitted by a He-Ne laser has a wavelength of 633 nm in air and travels at 3.00 × 10^8 m/s. Find the frequency of the laser light.
Any wave has three parameters, the velocity of the wave v, the frequency of the wave f and the wavelength w. These are related to each other by the relation v = w*f
The red-light of the He-Ne laser has a velocity 3*10^8 m/s. Its wavelength is 633 nm or 633*10^-9 m.
If the frequency of the wave is f, 3*10^8 = 633*10^-9*f
=> f = 3*10^8/633*10^-9 Hz
=> f = 4.739*10^14 Hz
The required frequency of the light emitted by the He-Ne laser is 4.739*10^14 Hz.