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.

Kilohertz-level spectroscopy of cold atoms with a femtosecond optical frequency comb



Tara Fortier, Yann Le Coq, Jason Stalnaker, Davi Ortega, Scott Diddams, Christopher W. Oates, Leo W. Hollberg


We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allowed for two regimes of amplification, one in which many teeth of the comb are amplified and one where a single tooth is predominantly amplified. The output of the laser in both regimes was used to perform kilohertz-level spectroscopy. This experiment demonstrates the potential for high-resolution absolute-frequency spectroscopy over the entire spectrum of the frequency comb output using a single high-finesse optical reference cavity.
Physical Review Letters


Fortier, T. , Le Coq, Y. , Stalnaker, J. , Ortega, D. , Diddams, S. , Oates, C. and Hollberg, L. (2006), Kilohertz-level spectroscopy of cold atoms with a femtosecond optical frequency comb, Physical Review Letters, [online], (Accessed July 18, 2024)


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

Created October 18, 2006, Updated October 12, 2021