Question

Write a report or information about optical resonators.

Answer 1

optical resonators

$\bigstar$

An optical resonator (or resonant optical cavity) is an arrangement of optical components

$\bull$ which allows a beam of light to circulate in a closed path.

$\bull$ Such resonators can be made in very different forms.

Various Types

$\bigstar$ Bulk-optical resonators

$\bull$ These are used for solid-state bulk lasers,

$\bull$ Their transverse mode properties depend on the overall setup (including the length of air spaces),

$\bull$ and mode sizes can vary significantly along the resonator.

$\bull$ In some cases, the mode properties are also significantly influenced by effects such as thermal lensing.

$\bigstar$ Waveguide resonators

$\bull$ These are often made with optical fibers 

$\bull$ (e.g. for fiber lasers) or in the form of integrated optics.

$\bull$ The transverse mode properties (see below) are determined by the local properties of the waveguide.

$\bigstar$ Mixed types

$\bull$ There are also mixed types of resonators, containing both waveguides and parts with free-space optical propagation.

$\bull$ Such resonators are used e.g. in some fiber lasers,

$\bull$ where bulk-optical components need to be inserted into the laser resonator.