초록 ▼

Raman spectrometer for analyzing the chemical composition of sample streams using an external cavity laser light source is disclosed. The laser provides an effective light source useful in continuously analyzing a sample stream containing petroleum products, aqueous or biological fluids, or solid sl

Raman spectrometer for analyzing the chemical composition of sample streams using an external cavity laser light source is disclosed. The laser provides an effective light source useful in continuously analyzing a sample stream containing petroleum products, aqueous or biological fluids, or solid slurries. The light is introduced into a bundle of optical fibers connected to a Raman sample cell. The Raman sample cell is configured to allow continuous sample flow therethrough. Scattered light from the sample cell preferably exits the optical fibers as a linear optical signal. A Raman spectrometer passes the optical signal through an excitation wavelength filter, an optical slit, and a volume holographic transmission grating with an aberration correction device before transmitting the optical signal to a charge coupled device array which converts the optical signal into a electronic signal. The electronic signal is analyzed and converted by computer into a representation of the chemical analysis of the sample stream.

대표청구항 ▼

[ What is claimed is:] [19.] An external cavity laser comprising:one or more diode laser emitters emitting light having an excitation wavelength;a collimating lens for receiving light from the one or more laser emitters, said collimating lens having a diameter sufficiently large to capture light emi

[ What is claimed is:] [19.] An external cavity laser comprising:one or more diode laser emitters emitting light having an excitation wavelength;a collimating lens for receiving light from the one or more laser emitters, said collimating lens having a diameter sufficiently large to capture light emitting from the one or more laser emitters;a volume holographic transmission grating positioned to receive light from the collimating lens, said grating being oriented at a non-normal angle relative to the light from the collimating lens, said volume holographic transmission grating having a plurality of grooves oriented parallel to the one or more laser emitters; anda power buildup cavity comprising two opposing mirrors, wherein one mirror is positioned to receive first order diffracted light from the volume holographic transmission grating and to reflect light back to the volume holographic diffraction grating to provide optical feedback to the one or more laser emitters.