Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A deep-UV optical frequency comb at 205 nm



Scott A. Diddams, E Peters, P Fendel, S Reinhardt, T W. Hansch, T Udem


By frequency quadrupling a picosecond pulse train from a Ti:sapphire laser at 820 nm we generate a frequency comb at 205 nm with nearly bandwidth-limited pulses. The nonlinear frequency conversion is accomplished by two successive frequency doubling stages that take place in resonant cavities that are matched to the pulse repetition rate of 82 MHz. This allows for an overall efficiency of 4.5 % and produces an output power of up to 70 mW for a few minutes and 25 mW with continuous operation for hours. Such a deep UV frequency comb may be employed for direct frequency comb spectroscopy in cases where it is less efficient to convert to these short wavelengths with continuous wave lasers.
Optics Express


ultraviolet laser, frequency comb, nonlinear optics


Diddams, S. , Peters, E. , Fendel, P. , Reinhardt, S. , Hansch, T. and Udem, T. (2009), A deep-UV optical frequency comb at 205 nm, Optics Express, [online], (Accessed June 18, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created May 25, 2009, Updated February 19, 2017