etalon

plural etalons

1. An optical device containing parallel mirrors, used as a narrow band filter, often in laser design.

   The laser output will be composed of longitudinal modes that fall inside the transmission band of the etalon, hence a narrowing of the laser line width is observed.

   2006, Walter Koechner, Solid-State Laser Engineering, page 264

   2 more examples

   It will be shown that the simple theory outlined in the preceding paragraph, which is applicable to single-plate etalons, can be used to predict the main features of the spectral curve of a multi element etalon.

   2004, S. C. Gupta, Textbook On Optical Fiber Communication And Its Applications, page 153

   The next step of this experiment is to compare the etalon m₁m₂ (shortest length) with the etalon m₃m₄ (the next one). For this two etalons are arranged side by side as shown in Fig. 7.13a.

   2009, V. Rajendran, Engineering Physics, page 7.15

   Synonyms: Fabry-Pérot interferometer