Broadband CO2 measurements with a VIPA spectrometer in the near-infrared

Abstract

We demonstrate near-infrared cavity-enhanced optical frequency comb spectroscopy of R branch of CO2 overtone transitions around 1.57μm. The measurement setup is based on an Er:fiber optical frequency comb, high finesse cavity and a VIPA spectrometer.A dither locking scheme provides robust operation and high absorption sensitivity enhancement, while a VIPA etalon-based spectrometer provides rapid broadband acquisition with 600 MHz spectral resolution. The sensitivity of the system reaches 2.3×10-9cm-1 at 2×82s acquisition time. We verify the resolution of the experimental setup by comparing the measured spectrum with the high-quality spectrum obtained with a cavity ring-down spectrometer.