Raman Spectroscopy Of Gases Research Articles

Azimuthal polarization for Raman enhancement in capillary waveguides

Hollow, metal-lined capillary waveguides have recently been utilized in spontaneous gas-Raman spectroscopy to improve signal strength and response time. The hollow waveguide is used to contain the sample gases, efficiently propagate a pump beam, and efficiently collect Raman scattering from those gases. Transmission losses in the waveguide may be reduced by using an azimuthally polarized pump beam instead of a linearly or radially polarized pump. This will lead to improved Raman signal strength, accuracy, and response time in waveguide-based Raman gas-composition sensors. A linearly polarized laser beam is azimuthally polarized using passive components including a spiral phase plate and an azimuthal-type linear analyzer element. Half-wave plates are then used to switch between the azimuthally polarized beam and the radially polarized beam with no change in input pump power. The collected Raman signal strength and laser throughput are improved when the azimuthally polarized pump is used. Optimization of the hollow waveguide Raman gas sensor is discussed with respect to incident pump polarization.

Boris Peter Stoicheff

Boris Peter Stoicheff

High-resolution Raman spectroscopy of gases and the determination of molecular bond lengths

High-resolution Raman spectroscopy of gases and the determination of molecular bond lengths

Raman spectroscopy of gases with a Fourier transform spectrometer: the spectrum of D_2

Fourier transform spectrometry (FTS) is presently used to record the spontaneous incoherent laser Raman spectra of gases. The high resolution, sensitivity, calibration accuracy and spectral coverage achieved demonstrate the viability of FTS for Raman spectroscopy. Attention is given to the coefficients obtained by fitting measurements obtained from the spectrum of D2, containing both v = 0-0 and 1-0 transitions, to the Dunham (1932) expansion of the vibration-rotation energy levels.

Raman spectroscopy of gases and liquids, Vol. 11 of topics in current physics

Raman spectroscopy of gases and liquids, Vol. 11 of topics in current physics

Raman Spectroscopy of Gases and Liquids

"Raman Spectroscopy of Gases and Liquids." Optica Acta: International Journal of Optics, 26(10), pp. 1239–1240