1201.5125 (Gabriel G. Ycas et al.)

Demonstration of On-Sky Calibration of Astronomical Spectra using a 25 GHz near-IR Laser Frequency Comb    [PDF]

Gabriel G. Ycas, Franklyn Quinlan, Scott A. Diddams, Steve Osterman, Suvrath Mahadevan, Stephen Redman, Ryan Terrien, Lawrence Ramsey, Chad F. Bender, Brandon Botzer, Steinn Sigurdsson

We describe and characterize a 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser. The comb provides a uniform array of optical frequencies spanning 1450 nm to 1700 nm, and is stabilized by use of a global positioning system referenced atomic clock. This comb was deployed at the 9.2 m Hobby-Eberly telescope at the McDonald Observatory where it was used as a radial velocity calibration source for the fiber-fed Pathfinder near-infrared spectrograph. Stellar targets were observed in three echelle orders over four nights, and radial velocity precision of ~10 m/s (~6 MHz) was achieved from the comb-calibrated spectra.

View original: http://arxiv.org/abs/1201.5125