What is Etalon in laser?
Etalons are based on the principle of the Fabry Perot Interferometer and are used to limit the wavelength ranges in laser cavities. They consist of two plane-parallel surfaces that are positioned at a fixed distance from each other. These etalons can be used as solid etalons or as air gap etalons.
What is Etalon effect?
An etalon is an optical interferometer that consists of two glass plates, separated by a small,flxed distance. A beam oflight undergoes multiple reflections between the surfaces of the glass plates. This results in optical transmission (or reflection) that is periodic in wavelength.
What is a Etalon used for?
Etalon is from the French étalon, meaning “measuring gauge” or “standard”. Etalons are widely used in telecommunications, lasers and spectroscopy to control and measure the wavelengths of light.
What is an Etalon Filter?
An etalon refers to an interference type filter typically used in Solar Telescopes because of the desire for an ultra narrow bandpass. An etalon is probably one of the simplest designs for an optical filter utilizing some of the most precise optical specifications. These optical surfaces are seperated by a gap.
Who invented Fabry-Perot interferometer?
Charles Fabry
The Fabry-Perot interferometer (FPI) was invented by the physicists Charles Fabry and Alfred Perot who published their most significant article in 1897 [5].
How do Etalon filters work?
A FP etalon is a type of “interference” filter which uses two highly polished, exceedingly flat, and precisely spaced partially reflective mirrors facing each other to achieve an ultra-narrow bandpass of usually less than ~ 0.1 nm (1 Ångstrom). The gap between the mirrors can be either solid or open (air-spaced).
Why we get circular fringes in Fabry-Perot interferometer?
The phase relationship between the transmitted rays depends on the angle at which each ray enters the cavity and on the distance between the two mirrors. The result is a circular fringe pattern, similar to the Michelson pattern, but with fringes that are thinner, brighter, and more widely spaced.