Differential high-resolution stimulated CW Raman spectroscopy of hydrogen in a hollow-core fiber.

We demonstrate sensitive high-resolution stimulated Raman measurements of hydrogen using a hollow-core photonic crystal fiber (HC-PCF). The Raman transition is pumped by a narrow linewidth (< 50 kHz) 1064 nm continuous-wave (CW) fiber laser. The probe light is produced by a homebuilt CW optical parametric oscillator (OPO), tunable from around 800 nm to 1300 nm (linewidth ∼ 5 MHz). These narrow linewidth lasers allow for an excellent spectral resolution of approximately 10(-4) cm(-1). The setup employs a differential measurement technique for noise rejection in the probe beam, which also eliminates background signals from the fiber. With the high sensitivity obtained, Raman signals were observed with only a few mW of optical power in both the pump and probe beams. This demonstration allows for high resolution Raman identification of molecules and quantification of Raman signal strengths.

[1]  T. A. Birks,et al.  Compact, stable and efficient all-fibre gas cells using hollow-core photonic crystal fibres , 2005, Nature.

[2]  Jürgen Popp,et al.  Fast and highly sensitive fiber-enhanced Raman spectroscopic monitoring of molecular H2 and CH4 for point-of-care diagnosis of malabsorption disorders in exhaled human breath. , 2015, Analytical chemistry.

[3]  R. Buczyński.  Photonic Crystal Fibers , 2004 .

[4]  F. Couny,et al.  Control of transient regime of stimulated Raman scattering using hollow-core PCF , 2009 .

[5]  R. Das,et al.  Raman spectroscopy: Recent advancements, techniques and applications , 2011 .

[6]  A. Eckbreth.  Laser Diagnostics for Combustion Temperature and Species , 1988 .

[7]  S. Wiberley,et al.  Introduction to infrared and Raman spectroscopy , 1965 .

[8]  A. Owyoung.  High-resolution cw stimulated Raman spectroscopy in molecular hydrogen. , 1978, Optics letters.

[9]  F. Benabid,et al.  Stimulated Raman Scattering in Hydrogen-Filled Hollow-Core Photonic Crystal Fiber , 2002, Science.

[10]  J. Murray,et al.  Effects of collisions on Raman line profiles of hydrogen and deuterium gas , 1972 .

[11]  F Benabid,et al.  Subwatt threshold cw Raman fiber-gas laser based on H2-filled hollow-core photonic crystal fiber. , 2007, Physical review letters.

[12]  Sensitivity enhancement in high resolution stimulated Raman spectroscopy of gases with hollow-core photonic crystal fibers. , 2013, Optics letters.

[13]  D E McClelland,et al.  Frequency locking a laser to an optical cavity by use of spatial mode interference. , 1999, Optics letters.

[14]  Dennis Weise,et al.  Continuous-wave 532-nm-pumped singly resonant optical parametric oscillator with periodically poled KTiOPO4 , 2000 .

[15]  P. Russell.  Photonic Crystal Fibers , 2003, Science.

[16]  Qiang Wang,et al.  High-sensitive measurement of water vapor: shot-noise level performance via a noise canceller. , 2013, Applied optics.

[17]  Jan Hald,et al.  Dynamics of gas flow in hollow core photonic bandgap fibers. , 2008, Applied optics.

[18]  Kevin P. Chen,et al.  Enhanced spontaneous Raman scattering and gas composition analysis using a photonic crystal fiber. , 2008, Applied optics.

[19]  Amir Abdolvand,et al.  Hollow-core photonic crystal fibres for gas-based nonlinear optics , 2014, Nature Photonics.

[20]  R. Bartlome,et al.  Trace gas monitoring with infrared laser-based detection schemes , 2008 .

[21]  Mortazavi,et al.  Supporting Online Material Materials and Methods Figs. S1 to S13 Tables S1 to S3 References Label-free Biomedical Imaging with High Sensitivity by Stimulated Raman Scattering Microscopy , 2022 .