title: Quantum-noise-limited optical frequency comb spectroscopy.
abstract: We achieve a quantum-noise-limited absorption sensitivity of 1.7×10(-12) cm(-1) per spectral element at 400 s of acquisition time with cavity-enhanced frequency comb spectroscopy, the highest demonstrated for a comb-based technique. The system comprises a frequency comb locked to a high-finesse cavity and a fast-scanning Fourier transform spectrometer with an ultralow-noise autobalancing detector. Spectra with a signal-to-noise ratio above 1000 and a resolution of 380 MHz are acquired within a few seconds. The measured absorption line shapes are in excellent agreement with theoretical predictions.
authors.affiliation: JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA. aleksandra.matyba@jila.colorado.edu
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Foltynowicz
authors.forename: Ticijana
authors.initials: T
authors.lastname: Ban
authors.forename: Piotr
authors.initials: P
authors.lastname: Masłowski
authors.forename: Florian
authors.initials: F
authors.lastname: Adler
authors.forename: Jun
authors.initials: J
authors.lastname: Ye