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Spectrometry and hyperspectral imaging are nding numerous applications for micro-optoelectrom echanical systems (MOE MS). A type of MOE MS device in the form of a digital micromirror array (DMA) has been m ade commercially available by Texas Instruments USA for projector display applications. We use this device as a spatial light modulator (SLM) in a new type of at-eld, nearinfrared dispersive spectrometer (NIRDM AS). Attributes of the DMA used in this manner are presented for discussion. Features that make a DM A attractive for spectrometry and imaging are describ ed. A brief introduction to H adamard transform (HT) techniques is presented to show that the DMA may be the best Hadamard encoding mask yet developed. A com parison of a conventional raster scanning (CRS) scan and a Hadamard transform spectrometry (HTS) scan with respect to the Hadamard multiplex advantage using a nonphoton noise-limited, single-element detector is presented. A signal-to-noise ratio comparison using four spectral lines from a m ercury-argon calibration lamp demonstrates that the theoretical noise reduction is approached for the HTS scan com pared to the CRS scan. Some future applications of M OEMS in spectrometry and hyperspectral im aging are suggested.

A successful interface between a high-performance liquid chromatograph and a Raman spectrometer is described. Surface-enhanced techniques are utilized to overcome the sensitivity problem inherent to conventional Raman spectrometry by adding a Ag sol to the chromatographic effluent in a post-column mixing coil. The system is designed so that Raman spectra may be obtained from chromatographic effluent or from flow injection analysis effluent. A common organic dye (pararosaniline hydrochloride) is used to evaluate the reproducibility, dynamic range, and analytical capabilities of the system. The SERS instrument is found to be a viable detector for HPLC and FIA, capable of providing structural information with a sensitivity comparable to that of other commonly used HPLC detectors.

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