We describe a successful effort to produce a laser comb around 1.55 μm in the astronomical H band using a method based on a line-referenced, electro-optical-modulation frequency comb. We discuss the experimental setup, laboratory results, and proof of concept demonstrations at the NASA Infrared Telescope Facility (IRTF) and the Keck-II telescope. The laser comb has a demonstrated stability of < 200 kHz, corresponding to a Doppler precision of ~0.3 m/s. This technology, when coupled with a high spectral resolution spectrograph, offers the promise of <1 m/s radial velocity precision suitable for the detection of Earth-sized planets in the habitable zones of cool M-type stars.
Physics, Astronomy, and Materials Science
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Yi, X., K. Vahala, J. Li, S. Diddams, G. Ycas, P. Plavchan, S. Leifer et al. "Demonstration of a near-IR line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy." Nature communications 7 (2016): 10436.