Noise-immune cavity-enhanced optical frequency comb spectroscopy.
Opt Lett
; 39(17): 5034-7, 2014 Sep 01.
Article
em En
| MEDLINE
| ID: mdl-25166067
ABSTRACT
We present a new method of optical frequency comb spectroscopy that combines cavity enhancement with frequency modulation to obtain immunity to laser frequency-to-amplitude noise conversion by the cavity modes and, thus, high absorption sensitivity over a broad spectral range. A frequency comb is locked to a cavity with a free spectral range (FSR) equal to 4/3 times the repetition rate of the laser, and phase-modulated at a frequency equal to the cavity FSR. The transmitted light is analyzed by a Fourier transform spectrometer with a high bandwidth detector. Phase-sensitive detection of the interferogram yields a noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS) signal. In the first demonstration, we record NICE-OFCS signals from the overtone CO2 band at 1575 nm with absorption sensitivity of 4.3×10(-10) cm(-1) Hz(-1/2) per spectral element, close to the shot noise limit.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Opt Lett
Ano de publicação:
2014
Tipo de documento:
Article