Abstract: An apparatus and method for optically measuring the functional capacity of blood platelets and the blood clotting system. The invention includes a mechanical specimen-handling apparatus with one or more optical end-point detectors. The apparatus incubates a small quantity of diluted whole blood with added solid or liquid reagents at body temperature, and mixes the blood via rocking and rotational motions so as to expose the blood uniformly to the reagents. The optical end-point detectors then measure the activity of platelets within the blood specimen and the clotting cascade. Several intermediate measures are also available.

Abstract: The liquid nephelometer has an elongate, tubular housing for containing a liquid sample to be measured for the concentration of foreign materials, a light source located adjacent one or both ends of the housing for directing a beam of light along an axial path through the housing, a light restrictor having a aperture of reduced cross sectional area to divide the interior of the housing into a first or sensing chamber having a known volume and a second chamber and to limit the passage of the scattered light between the two chambers, and light detecting means for detecting light scattered by foreign material in the liquid present in one or both of the chambers and producing a signal representative of the concentration of such foreign material.

Abstract: A reflection densitometer includes a light source and a photodetector having an output which has a signal component characteristic of the amount of reflected light received from a surface to be measured and a noise component. The noise component of the output is isolated in time by switching the light source on and off so as to create alternating first and second time periods during which the output of the photodetector is characteristic of only the noise component and in which the output of the photodetector is characteristic of both the signal component plus the noise component, respectively. The output of the photodetector during the second time period is subtracted from the output during the first time period to obtain a signal characteristic of only the output of the photodetector characteristic of relected light received.

Abstract: A dither motor for dithering a plurality of inertial sensors includes an outer support ring, a plurality of reeds and a plurality of mounting supports. The outer support ring may be generally circular or polygonal in shape. Each reed of the plurality of reeds has a hub end and an outer end wherein the hub ends are connected to a common hub and the ring ends are connected to the outer support ring. The plurality of reeds are arranged to be disposed at equal angles from each other and extend radially outwardly from the hub. The plurality of mounting supports extend outwardly from the hub and each mounting support is located between two of the plurality of reeds. The mounting supports are also equally spaced apart. Further, each reed has a means for oscillating connected thereto such as piezoelectric elements.

Abstract: A displacement detector device has a source of laser beam; a diffraction grating for separating the laser beam into a plurality of beam components; a filter for shielding the beam components other than the two beam components of .+-. primary order produced by the diffraction grating; a wavelength plate operable to vary the polarized state of one of the two beam components of .+-. primary order; a lens element for focusing the two beam components of .+-. primary order on a displacement plane and a reference plane, respectively; and a photosensor. The two beam components of .+-. primary order focused on the reference and displacement planes, respectively, are subsequently reflected therefrom and are then collimated by the lens element after having again entered the lens element in substantially overlapped relationship.

Abstract: In a ring resonator gyro the CW and CCW beams are modulated to provide each with a spectrum including a carrier and an upper and a lower side band. The upper side band of one beam is kept at a resonance by a path length control loop 24 and the upper side band of the other beam is kept at a resonance by a rate control loop 40.

Abstract: A media discriminating and presence sensor that can detect and discriminate between paper and transparency uses a light emitting diode and two defectors configured so as to measure both diffuse and specular reflectivity of the media, and a media support surface that suppresses unwanted reflections.

Abstract: A laser system for measuring dimensional aberrations across a target surface includes a laser diode for producing a diverging beam of laser emission. A mask spaced from the diode in the beam has an aperture therein and can be moved so as to translate the aperture to selected locations laterally with respect to the beam. The mask blocks emission from impinging on the target except for emission transitting the aperture. Emission reflected from a segment to the target returns through the aperture back into the laser diode. An AC current is added to the driver current to modulate the emission. A lock-in amplifier of a photodetector signal adds feedback current to the driver current to lock in phase angle, so that the feedback current is a measure of the aberrations.

Abstract: An acousto-optic spectrometer/polarimeter for analyzing an incident broad-band beam including an acousto-optic tunable filter (AOTF) for separating the incident broad-band beam into a diffracted extraordinary narrow-band beam, a diffracted ordinary narrow-band beam, and at least one undiffracted broad-band beam; first, second and third detectors respectively positioned to respectfully receive at least a portion of the diffracted extraordinary narrow-band beam, the diffracted ordinary narrow broad-band beam and the at least one undiffracted broad-band beam, and to respectively provide first, second and third signals based thereon; a subtracter for providing a polarimeter output by taking the difference between the first and the second signals; and an adder for providing a spectrometer output by adding the first and the second signals.

Abstract: A probe for in situ quantitative detection of the concentration of an analyte in a sample includes a hollow elongated body adapted for single ended contact with the sample. The body has at least one optical fiber extended through the body for transmitting modulated light through the body, out a window at the forward end of the body, and along an optical axis into the sample to optically excite the analyte. A pressure transducer mounted beyond the window and spaced laterally away from the optical axis detects an acoustic response of the analyte to the modulated light. This probe is particularly suitable for performing remote photoacoustic analysis of analyte concentration in a sample.

Abstract: In a fiber optic interferometer rotation rate sensor reset by phase ramp via a digital control circuit to undertake the reversal required to obtain the scale factor error information, a reciprocal, alternating phase shift that is not a function of the angle of rotation, but has a fixed timing, is synchronized with gyroscope modulation frequency to avoid lock-in, and scale factor nonlinearities, particularly in the case of low rates of rotation. Even in the case of low rates of rotation, a scale factor error correction is possible and lock-in, caused by variations in bias in the case of the modulation deviation reversal, is avoided.

Abstract: An apparatus (10) designed to evaluate ion implantation levels in semiconductor samples (42) is disclosed. The device includes an intensity modulated pump laser beam (22) and a probe beam (62) having a different wavelength than the pump beam. The two laser beams are focused on a coincident spot on the surface of the sample. Detectors (80, 96) are provided for measuring the non-modulated reflected power of the pump and probe beams. In addition, the modulated reflected power of the probe beam, that is in phase with the intensity modulated pump beam, is also measured. These three independent measurements are utilized to derive the implant dosage level in the semiconductor sample.

Abstract: An optoelectronic device is provided which permits rapid sequential measurement of the optical density of multiple samples. The device employs a plurality of light-emitting diodes (LEDs) as light sources and a plurality of photodiodes as light detectors. In a preferred embodiment, arrays of LEDs paired with photodiodes are adapted to measure the optical density of samples contained in multiwell plastic plates (microplates) conventionally used for immunoassays.

Abstract: An apparatus for the analysis of a fluid flowing in a stream includes opposed hollow stems movable in a body member relative to each other. One stem contains a signalling source and the other contains a sensor for the signalling source.

Abstract: A method and apparatus are shown to measure unburned carbon particles in the exhaust of a combustor. Photoacoustic absorption spectrometry is employed to measure the presence of the unburned carbon. Especially helpful in these measurements is a vertically elongated photoacoustic cell in which high flow velocities are maintained to prevent particles from settling. These measurements are useful in determining the efficiency of coal-fired combustors.

Abstract: A high speed wideband silicon photodetector is formed from a photosensitive junction in a relatively thin epitaxial layer of silicon grown on a sapphire substrate using SOS technology. The photodetector is backside illuminated, that is, illumination to be detected is cause to strike a receptor surface of the sapphire substrate so that it can reach the photosensitive junction in the silicon layer even with the shallower minimum penetration depths available at higher frequencies. A bias voltage may be applied to extend the depletion region from the photosensitive junction to the silicon sapphire interface. A magnesium fluoride anti-reflective coating may be used on the sapphire reflective surface.