Question

A certain laser design uses a cavity of length 250 micrometers with reflectivity R=0.45.
The refractive index of the material in 2.7 and peak wavelength is at 530 nm with a linewidth
of 6 nm. Is this laser a single-mode laser? Explain in details.

Answer 1

This is not a single-mode laser by the given requirements. Here we calculated line width using condition of a standing wave in a Fabry Perot resonator and compared it with the given value of the linewidth. These do not match.