Operation of a broadband visible-wavelength astro-comb with a high-resolution astrophysical spectrograph

• DOI: 10.1364/optica.2.000250
• Publication Date: 2015-03-10T15:34:11Z
• Authors: Alexander G. Glenday; Chih-Hao Li; Nicholas Langellier; Guoqing Chang; Li-Jin Chen; Gabor Furesz; Alexander A. Zibrov; Franz Kärtner; David F. Phillips; Dimitar Sasselov; Andrew Szentgyorgyi; Ronald L. Walsworth
• Keywords: Visible spectrum

Searches for Earth-like exoplanets using the periodic Doppler shift of stellar absorption lines require 10 cm/s precision in measurement radial velocity (RV) over timescales years. Current techniques have led to discovery short-period that induce RV wobbles as small ≈1 m/s on their parent stars. It has been suggested order-of-magnitude improved may be achievable an astro-comb, a laser frequency comb optimized astrophysical spectrograph wavelength calibration. Here we report development broadband visible-wavelength astro-comb and its operation with HARPS-N at Telescopio Nazionale Galileo Canary Islands. This green >7000 narrow (<1 MHz) spectral spaced by 16 GHz relatively uniform line power from 500 620 nm. The frequencies are locked GPS, enabling us realize calibration stability <10 cm/s.