Name three approaches of how single mode laser can be obtain

Name three approaches of how single mode laser can be obtained. Explain each approach.

Solution

Single-mode Operation:

operation of a laser on axial (longitudinal) resonator modes only, or even on a single axial mode.

The term single-mode operation, which usually applies to lasers, is ambiguous, as it is used with different meanings:

The number and type of oscillating resonator modes in a laser depends on the circumstances: