The Grating Light Valve TM (GLV TM ) is a diffractive MOEMS spatial light modulator capable of very high-speed modulation of light combined with fine gray-scale attenuation. GLV-based products are field-proven in a variety of applications. In this paper, we describe the GLV device, its structure, theory of operation, and optical performance. The versatility and speed of the GLV device are described. We explain how the GLV device is integrated into an optical write engine to create a complete digital imaging system. In addition to the MOEMS die and drive electronics, the light engine also comprises illumination optics, Fourier filter, and imaging optics. We present current applications of the GLV device for high-resolution displays, and computer-to-plate printing, as well as future plans for digital imaging applications opened up by the unique properties of this diffractive MOEMS technology.

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We have observed some of the absorption lines from the molecules (12)CO(2) and (13)CO(2)in the 1.6-µm spectral region with the use of specially fabricated single-mode InGaAsP distributed-feedback semiconductor diode lasers. Using a 23.6-m-long multipass absorption cell in combination with radio-frequency modulation and detection techniques, we measured the (12)CO(2):(13)CO(2) isotopic ratio of two specific lines at 6253.73 and 6253.90 cm(-1) with sufficient precision for diagnostic medical tests that analyze CO(2) on human breath.

This paper reports the demonstration of quantum-noise-limited sensitivity in frequency modulation spectroscopy (FMS) with a lead-salt diode laser operating in the 4.8-microm region. Experimentally determined sensitivities of 10(-7) in a 1-Hz bandwidth have been demonstrated for detection of CO and CO(2) in a single-pass absorption cell. The high sensitivity obtained with our FMS apparatus can be attributed to the use of improved lead-salt diode lasers, a new optical fringe reduction method, and careful attention to optical processing of the diode laser beam.

A recursive Kalman time-series filter was applied to absorbance measurements obtained with a tunable diode laser spectrometer. The spectrometer uses frequency modulation spectroscopy and a nearinfrared diode laser operating at 1.604 µm to monitor the CO(2)-vapor concentration in a 30-cm absorption cell. The Kalman filter enhanced the signal-to-noise ratio of the spectrometer by an order of magnitude when an absorbance of 6 × 10(-5) was monitored.