Narrowing of the linewidth of an optical parametric oscillator by an acousto-optic modulator for the realization of mid-IR noise-immune cavity-enhanced optical heterodyne molecular spectrometry down to 10(-10) cm(-1) Hz(-1/2)

作者：Hausmaninger Thomas; Silander Isak; Axner Ove

来源：Optics Express, 2015, 23(26): 33641-33655.

DOI：10.1364/OE.23.033641

The linewidth of a singly resonant optical parametric oscillator (OPO) has been narrowed with respect to an external cavity by the use of an acousto-optic modulator (AOM). This made possible an improvement of the sensitivity of a previously realized OPO-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry instrument for the 3.2 - 3.9 mu m mid-infrared region by one order of magnitude. The resulting system shows a detection sensitivity for methane of 2.4 x 10(-10) cm(-1) Hz(-1/2) and 1.3 x 10(-10) cm(-1) at 20 s, which allows for detection of both the environmentally important (CH4)-C-13 and CH3D isotopologues in atmospheric samples.

• 出版日期2015-12-28