Precision astrophysical spectroscopy is a crucial tool for cosmology and the study of planets around other stars (exoplanets), but is currently limited by the stability and precision of existing wavelength calibration sources. I will describe our realization of a near-IR laser comb with up to 40 GHz line-spacing, generated from a 1-GHz repetition-rate source comb and Fabry-Perot filtering cavity, as an improved wavelength calibrator; integration and testing of this "astro-comb" with a telescope and precision spectrograph at the Whipple Observatory in Arizona; and ongoing development of astro-combs operating in the visible, to enable searches for Earth-like exoplanets. Astro-combs should allow more than an order-of-magnitude improvement in sensitivity to changes in Doppler-shifts and cosmological redshifts, with significant impact on many fields.

Argonne Physics Division Colloquium Schedule