Vainio M, Siltanen M, Peltola J, Halonen L. Grating-cavity continuous-wave optical parametric oscillators for high-resolution mid-infrared spectroscopy.
APPLIED OPTICS 2011;
50:A1-A10. [PMID:
21283213 DOI:
10.1364/ao.50.0000a1]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The use of grating as a spectral filter provides a simple way of improving wavelength tuning and stability of continuous-wave optical parametric oscillators (cw OPOs). In this paper, we discuss how to design and use such grating-cavity cw OPOs for high-resolution spectroscopy in the molecular fingerprint region at ∼3μm. The first design presented in the paper is based on a metal-coated diffraction grating, which produces fast and broad wavelength tuning and high wavelength stability. The second design uses a bulk Bragg grating for high optical power and good spectral purity. We report a new Bragg-grating OPO and demonstrate its use in a Doppler-free absorption spectroscopy of CH4 at ∼3.22μm. In addition, we describe a new balanced detection scheme, which can be used to improve the signal-to-noise ratio of absorption measurements if the measurement noise is limited by the intensity noise of the mid-infrared OPO.
Collapse