Visible astro-comb filtered by a passively stabilized Fabry-Perot cavity

We demonstrate a compact 29.3 GHz visible astro-comb covering the spectrum from 560 nm to 700 nm. A 837 MHz Yb:fiber laser frequency comb phase locked to a Rb clock served as the seed comb to ensure the frequency stability and high side mode suppression ratio. After the visible super-continuum generation, a Fabry-Perot cavity based on ultra-low expansion glass was utilized to filter the comb teeth. The mirrors were home-made complementary chirped mirrors pair with zero net-dispersion and high reflection to guarantee no mode skipping. Those filtered comb teeth were clearly resolved in an astronomical spectrograph of 49 000 resolution, exhibiting sharp line shape, zero noise floor, and uniform exposure amplitude.