Green astro-comb for exoplanet searches: improved hardware and operation

POSTER

Abstract

Searches for extrasolar planets using the precision stellar radial velocity (RV) measurement technique are approaching Earth-like planet sensitivity. Astro-combs, which consist of a laser frequency comb, coherent wavelength shifting mechanism (such as a doubling crystal and photonic crystal fiber), and a mode-filtering Fabry-Perot cavity (FPC), provide a promising route to increased accuracy and long-term stability on the astrophysical spectrograph calibration. We present the design of a green astro-comb from an octave spanning Ti:Sapphire laser, spectrally broadened by custom tapered PCF to the visible band via fiber-optic Cherenkov radiation for frequency shifting, and filtered by a broadband FPC, constructed by a pair of complementary chirped mirrors. Performance of this astro-comb and enhancements for improved operation at the HARPS-N spectrograph will be presented.

Authors

  • Nicholas Langellier

    • Harvard-Smithsonian Center for Astrophysics

  • Nabila Tanjeem

    • Harvard-Smithsonian Center for Astrophysics

  • Alexander Glenday

    • Harvard-Smithsonian Center for Astrophysics

  • Chih-Hao Li

    • Harvard-Smithsonian Center for Astrophysics

  • Gabor Furesz

    • Harvard-Smithsonian Center for Astrophysics

  • David Phillips

    • Harvard-Smithsonian Center for Astrophysics

  • Guoqing Chang

    • Physics. Dept. Hamburg University and DESY and MIT
    • Physics Dept., Hamburg University, DESY and MIT

  • Hung-Wen Chen

    • Massachusetts Institute of Technology

  • Jinkang Lim

    • Massachusetts Institute of Technology

  • Franz Kaertner

    • Physics. Dept. Hamburg University and DESY and MIT
    • Physics Dept., Hamburg University, DESY and MIT

  • Andrew Szentgyorgyi

    • Harvard-Smithsonian Center for Astrophysics

  • Ron Walsworth

    • Harvard-Smithsonian Center for Astrophysics
    • Harvard University