Monterey Bay Aquarium Research Institute
Laser Raman Spectroscopy

DORISS is based on a laboratory model laser Raman spectrometer from Kaiser Optical Systems, Inc. The instrument consists of a Kaiser HoloSpec f/1.8i spectrometer with a holographic duplex transmission grating and a front illuminated CCD camera from Andor Technology; a 100 mW, 532 nm Nd:YAG laser; and a holographically filtered probe head with interchangeable sampling optics. We use a 2.5 inch stand-off optic behind a dome window and an immersion optic which protrudes through a titanium endcap into seawater. The components are divided into three pressure housing for deployment to depths of upto 4000 m in the ocean.

The Spectrometer Housing is ~76 cm long and 32 cm in diameter, with a 22 cm-long extension at a 90 degree angle to contain the CCD camera. The housing is 7075 aluminum. It contains the optical bench/spectrometer, CCD camera with associated electronics, and temperature and humidity sensors.

The Electronics Housing is a 100 cm long, 25.4 cm diameter fiberglass pressure housing. It holds a single-board computer, the 532 nm laser, and temperature and humidity sensors. (The power inverter has been removed and is no longer necessary).

The Probe Head Housing is titanium and is 35.5 cm long and 14 cm in diameter. It contains the optical probe head and is contected to the laser and the spectrometer via pressure-tolerant fiber optic cables. The stand-off optic is used behind the dome window. The immersion optic is used with a flat endcap with a pressure gland seal.

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Last updated: Feb. 05, 2009
Questions? Comments? Please contact Edward Peltzer.