![Frequency combs, explained by RP; optical ruler, mode-locked laser, metrology, self-referencing, f--2f, noise, Hall, Hänsch, Nobel Prize Frequency combs, explained by RP; optical ruler, mode-locked laser, metrology, self-referencing, f--2f, noise, Hall, Hänsch, Nobel Prize](https://www.rp-photonics.com/img/comb.png)
Frequency combs, explained by RP; optical ruler, mode-locked laser, metrology, self-referencing, f--2f, noise, Hall, Hänsch, Nobel Prize
Laser light of a specific frequency falls on a crystal that converts this light into one with double the original frequency. Suppose the original laser light was red. In which region of
![Wavelength References: Tunable laser, frequency combs, and integrated photonics forge an optical frequency synthesizer | Laser Focus World Wavelength References: Tunable laser, frequency combs, and integrated photonics forge an optical frequency synthesizer | Laser Focus World](https://img.laserfocusworld.com/files/base/ebm/lfw/image/2018/09/content_dam_lfw_print_articles_2018_09_1809lfw_wn_f3.png?auto=format%2Ccompress&w=320)
Wavelength References: Tunable laser, frequency combs, and integrated photonics forge an optical frequency synthesizer | Laser Focus World
![Advancing frequency locking: Modified FPGA-Guided direct modulation spectroscopy for laser stabilization - ScienceDirect Advancing frequency locking: Modified FPGA-Guided direct modulation spectroscopy for laser stabilization - ScienceDirect](https://ars.els-cdn.com/content/image/1-s2.0-S0030399223011404-gr6.jpg)