Open AccessSelf-heterodyne interference spectroscopy using a comb generated by pseudo-random modulation
Author(s) -
Nicolas Bourbeau Hébert,
Vincent Michaud-Belleau,
James Anstie,
Jean-Daniel Deschênes,
André Luiten,
Jérôme Genest
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.027806
Subject(s) - optics , frequency comb , heterodyne (poetry) , laser , heterodyne detection , spectroscopy , modulation (music) , physics , phase modulation , spectrometer , comb generator , wavelength , continuous wave , frequency modulation , bandwidth (computing) , phase noise , telecommunications , computer science , quantum mechanics , acoustics
We present an original instrument designed to accomplish high-speed spectroscopy of individual optical lines based on a frequency comb generated by pseudo-random phase modulation of a continuous-wave (CW) laser. This approach delivers efficient usage of the laser power as well as independent control over the spectral point spacing, bandwidth and central wavelength of the comb. The comb is mixed with a local oscillator generated from the same CW laser frequency-shifted by an acousto-optic modulator, enabling a self-heterodyne detection scheme. The current configuration offers a calibrated spectrum every 1.12 µs. We demonstrate the capabilities of the spectrometer by producing averaged, as well as time-resolved, spectra of the D1 transition of cesium with a 9.8-MHz point spacing, a 50-kHz resolution and a span of more than 3 GHz. The spectra obtained after 1 ms of averaging are fitted with complex Voigt profiles that return parameters in good agreement with expected values.