Abstract: The fiber optic pressure sensing system includes a sensor housing formed using MEMS processing. The sensor housing has ribs and grooves in both horizontal and vertical directions relative to the surface to allow the membrane to flex in a consistent manner. The flexing of the membrane allows the pedestal to be repeatedly positioned in response to pressure acting on the extension of the sensor head and membrane.

Abstract: The fiber optic pressure sensing system includes a sensor housing formed using MEMS processing. The sensor housing has ribs and grooves in both horizontal and vertical directions relative to the surface to allow the membrane to flex in a consistent manner. The flexing of the membrane allows the pedestal to be repeatedly positioned in response to pressure acting on the extension of the sensor head and membrane.

Abstract: A holographic scatterometer with continuous readout can rapidly identify the presence of deposits (particles or other defects) on an unpatterned wafer surface and determine the volume density (size) and location. The scatterometer can also determine chemical composition of the detected deposits. The range of the deposit (particle) size to be measured is below 80 nm, which currently existing scatterometer type instruments cannot readily detect. The inspection can be achieved as an in-line stage during the processing of wafers or in situ in combination with another processing tool or as a separate off-line analysis device.

Abstract: A holographic scatterometer with continuous readout can rapidly identify the presence of deposits (particles or other defects) on an unpatterned wafer surface and determine the volume density (size) and location. The scatterometer can also determine chemical composition of the detected deposits. The range of the deposit (particle) size to be measured is below 80 nm, which currently existing scatterometer type instruments cannot readily detect. The inspection can be achieved as an in-line stage during the processing of wafers or in situ in combination with another processing tool or as a separate off-line analysis device.

Abstract: A visibility sensor system includes a housing having a sensor head opening. A removable sensor head assembly is removably coupled to the housing within the sensor head opening. The sensor head assembly has a sensor enclosure and a connector. An electronics module is coupled to the sensor head through the connector. A rain sensor determines the presence of rain and causes shutters to cover openings in the sensor exclosure. In other embodiments, the sensor enclosure is configured to develop a pressure differential internally to minimize contamination of light source and light detector.

Abstract: A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

Abstract: A fiber optic pressure catheter includes a light source, an optical fiber coupled to receive light from the light source and a sensor head that is optically coupled to the optical fiber. The sensor head has a housing defining a chamber coupled to an end of the optical fiber opposite the light source. The housing has an opening which is enclosed by a membrane. The membrane is responsive to pressure differentials between the chamber and outside the sensor head. A resilient ribbon is coupled within the chamber and has a first end fixedly coupled to a support. The ribbon has a second end that is movable in front of the optical fiber. The ribbon is mounted so that the middle portion of the ribbon touches the membrane and is biased by the membrane in response to various pressure differentials. Thus, various amounts of light are reflected back into the optical fiber based on the amount of pressure at the membrane.

Abstract: A visibility sensor system includes a housing having a sensor head opening. A removable sensor head assembly is removably coupled to the housing within the sensor head opening. The sensor head assembly has a sensor enclosure and a connector. An electronics module is coupled to the sensor head through the connector.

Abstract: A scatterometer for detecting and analyzing wafer surface defects includes a light source generating a beam of light and a photodetector. Optics are used for splitting the beam of light into a reference beam and a detection beam. Optics also direct the reference beam and the detection beam to the photodetector through different optical paths. The optics direct the detection beam to the surface of the wafer and when incident upon a defect creates a scattered beam. The optics direct the scattered beam to the photodetector. A driver moves the surface of the wafer with respect to the detection beam. A computer coupled to the photodetector determines the presence of a defect on the surface by analyzing an interference pattern from the superposition of the reference beam and the scattered beam.

Abstract: A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

Abstract: The present invention describes a method and apparatus for monitoring and indicating engine oil deterioration during the period of the oil's useful life in an internal combustion engine. The system and method permits a determination of the rate of deterioration of the engine oil as a function of oil temperature or RPM of the engine and provides a continous output signal representing the remaining useful life of the oil which is provided to the driver when desired. The present invention therefore, estimates the time when the oil will reach an undesirable deterioration level during the course of operation of the engine rather than indicating, as many prior art systems, only when the oil reaches an undesirable level requiring an oil change.

Abstract: The elevation angle of a low angle target is accurately measured by subtracting from the received radar signal signals derived from an estimated value of target elevation which reduces the resulting signal to a minimum. The estimated value is an accurate measure of target elevation.

Abstract: An underwater viewing system described herein substantially reduces the number of hydrophones in the receiving array and associated circuitry by providing a plurality of transmitting transducers spaced apart by a known distance, each emitting a coded output which is normally a separate frequency. The receiving array, which is preferably square or rectangular, includes a substantial number of receiving hydrophones.A synthetic aperture technique is applied in which the reflected signal arriving at each individual hydrophone is amplified, modulated with a lower frequency reference signal, filtered, digitized and stored in a memory, preferably as part of a computer. The computer also compares each digitized hydrophone signal against sine and cosine reference signals at each frequency and performs a Fourier analysis of each row and column to reconstruct a primary image.

Abstract: An arrangement for measuring the profile of surfaces having a characteristic one-directional lay with sufficient resolution to determine the surface roughness thereof is disclosed, comprising a device for illuminating a small spot on the surface, with an image of the spot projected through an objective lens onto a large area light detector positioned to generate a signal corresponding to the total illumination produced by the image. The device also includes a second light detector which views a second image of the spot focused by the objective lens through a slit disposed perpendicularly to the direction of the surface lay. The respective detector signals are divided to produce signals corresponding to the ratio thereof, which, according to the present invention, correspond to the variations of the surface height occuring as the illuminated spot is scanned across the surface. A graphical profile of the surface may be obtained by recording these signals as a function of the scanned distance.