10 Facts About Frequency comb

In optics, a frequency comb is a laser source whose spectrum consists of a series of discrete, equally spaced frequency lines.

Frequency domain representation of a perfect frequency comb is a series of delta functions spaced according to.

Any mechanism by which the combs' two degrees of freedom are stabilized generates a comb that is useful for mapping optical frequencies into the radio frequency for the direct measurement of optical frequency.

Therefore, a conceptually simple way to make an optical frequency comb is to take two high-power lasers of slightly different frequency and shine them simultaneously through a photonic-crystal fiber.

Many applications, the comb must be widened to at least an octave: that is, the highest frequency in the spectrum must be at least twice the lowest frequency.

Breakthrough which led to a practical frequency comb was the development of technology for stabilizing the carrier–envelope offset frequency.

Frequency comb allows a direct link from radio frequency standards to optical frequencies.

Current frequency standards such as atomic clocks operate in the microwave region of the spectrum, and the frequency comb brings the accuracy of such clocks into the optical part of the electromagnetic spectrum.

In recent years, the frequency comb has been garnering interest for astro-comb applications, extending the use of the technique as a spectrographic observational tool in astronomy.

Also in 2005, the femtosecond comb technique was extended to the extreme ultraviolet range, enabling frequency metrology in that region of the spectrum.