Frequency comb (頻率梳)

 A frequency comb or spectral comb is represented by a spectrum made of discrete, stable and regularly spaced spectral lines. In optics, a frequency comb can be generated by certain laser sources.

A number of mechanisms exist for obtaining an optical frequency comb, including periodic modulation (in amplitude and/or phase) of a continuous-wave laser, four-wave mixing in nonlinear media, or stabilization of the pulse train generated by a mode-locked laser. Much work has been devoted to this last mechanism, which was developed around the turn of the 21st century and ultimately led to one half of the Nobel Prize in Physics being shared by John L. Hall and Theodor W. Hänsch in 2005.

頻率梳（frequency comb）或光譜梳（spectral comb）是由離散、穩定且具備等間距光譜線所組成的光譜。在光學中，頻率梳可以透過特定的雷射源來產生。

獲得光學頻率梳的機制有多種，包括對連續波雷射進行週期性調變（振幅和／或相位）、在非線性介質中進行四波混頻，或是對鎖模雷射所產生的脈衝序列進行穩頻。許多研究都投入在最後這項機制上；該機制於 21 世紀初發展成熟，並最終促使約翰·霍爾（John L. Hall）與特奧多爾·亨施（Theodor W. Hänsch）共同榮獲 2005 年諾貝爾物理學獎的一半獎項。