Abstract: A particle counter for optically detecting an unconstrained particle of less than one micron in size suspended in a flowing liquid includes a sample chamber having a fluid inlet and a fluid outlet; a laser module producing a laser beam; a beam shaping optical system providing a multiple laser beam pattern in the sample chamber; and a CMOS optical detector located to detect light scattered by the particles in the sample chamber. The particle counter has a particle sensing area within the sample chamber in which the intensity of light is at least 10 Watts/mm2, the sensing area having an area of 0.5 square mm or more. The detector has thirty or more detector array elements. In the preferred embodiment, the laser optical system reflects and refocuses the laser beam to effect multiple passes of the same laser beam through the sensing area.

Abstract: A particle counter for optically detecting an unconstrained particle of less than one micron in size suspended in a flowing liquid includes a sample chamber having a fluid inlet and a fluid outlet; a laser module producing a laser beam; a beam shaping optical system providing a multiple laser beam pattern in the sample chamber, and a CMOS optical detector located to detect light scattered by the particles in the sample chamber. The particle counter has a particle sensing area within the sample chamber in which the intensity of light is at least 10 Watts/mm2, the sensing area having an area of 0.5 square mm or more. The detector has thirty or more detector array elements. In the preferred embodiment, the laser optical system reflects and refocuses the laser beam to effect multiple passes of the same laser beam through the sensing area.

Abstract: The invention describes the first practical, cost effective, truly non-contact implementation of a subcutaneous vein pattern biometric sensor. A laser diode (LD) illuminates the hand in such a way that the pattern of reflected radiation, when viewed by a conventional vein pattern infrared imager, provides a direct measure of target range. Said target range measurement is used to create a visual or audio signal that instructs the individual being scanned to place the hand at precisely the optimum range, such that the vein pattern is in focus. Furthermore, a system and apparatus are described to direct the individual being scanned to move the hand to an optimal horizontal registration or position with respect to the infrared imager.

Abstract: A particle counter for optically detecting an unconstrained particle of less than one micron in size suspended in a flowing liquid includes a sample chamber having a fluid inlet and a fluid outlet; a laser module producing a laser beam; a beam shaping optical system providing a multiple laser beam pattern in the sample chamber, and a CMOS optical detector located to detect light scattered by the particles in the sample chamber, the detector producing an electric signal characteristic of a parameter of the particle. The particle counter has a particle sensing area within the sample chamber in which the intensity of light is at least 10 Watts/mm2, the sensing area having an area of 0.5 square mm or more. The detector has thirty or more detector array elements. In the preferred embodiment, the laser optical system reflects and refocuses the laser beam to effect multiple passes of the same laser beam through the sensing area.

Abstract: An opaque slurry chemical constituent measurement system includes a cross-flow or membrane filter having a porous filter element connected between a global slurry loop and a spectrometer. The opaque slurry particles cannot pass through the filter element but pass through the filter cartridge into the day tank, while the chemical constituent to be measured permeates through the filter element to the spectrometer, where it is measured, and thence to a reservoir. About once every five minutes the porous filter element is reverse flushed for less than a second to clear the filter pores. One to several times per hour, the reservoir is emptied into the day tank. The system provides essentially continuous measurement of the slurry chemical composition, does not consume reagent chemicals, does not create a chemical waste stream, and provides high reliability and low maintenance by preventing the abrasive slurry particles from contacting the fluidic sampling valves.

Abstract: A fluid particle counter comprising an intracavity diode pumped solid state laser having a solid state lasing material having a non-reflective coating and a concave mirror having a reflective coating, with the coatings isolated from the sample flow by Brewster windows. The laser beam is apertured by an aperture assembly including an inner aperture closest to the inlet nozzle assembly and an outer aperture farther from the inlet nozzle assembly, with the outer aperture significantly farther from the inner aperture than the inner aperture is from the inlet nozzle assembly.

Abstract: An opaque slurry chemical constituent measurement system includes a cross-flow or membrane filter having a porous filter element connected between a global slurry loop and a spectrometer. The opaque slurry particles cannot pass through the filter element but pass through the filter cartridge into the day tank, while the chemical constituent to be measured permeates through the filter element to the spectrometer, where it is measured, and thence to a reservoir. About once every five minutes the porous filter element is reverse flushed for less than a second to clear the filter pores. One to several times per hour, the reservoir is emptied into the day tank. The system provides essentially continuous measurement of the slurry chemical composition, does not consume reagent chemicals, does not create a chemical waste stream, and provides high reliability and low maintenance by preventing the abrasive slurry particles from contacting the fluidic sampling valves.

Abstract: An optical particle counter has a gain-apertured laser cavity producing laser light, an inlet jet providing fluid flow into a particle detecting region within the laser cavity, the inlet jet having an inlet jet orifice; a detection optics assembly located to collect light scattered from particles with the detecting region for producing an output signal indicative of the particles; and an optical barrier complex located to reduce noise as compared to the gain-apertured system without the optical barrier complex for fluid flow rates greater than or equal to about 0.1 cubic feet per minute. The optical barrier complex inhibits laser light from illuminating turbulent eddy currents originating on the interior walls of the inlet jet. The optical barrier complex includes one or more physical apertures, one or more optical stops, or both which are located to prevent laser light from illuminating the eddy currents.

Abstract: An optical particle counter has a gain-apertured laser cavity producing laser light, an inlet jet providing fluid flow into a particle detecting region within the laser cavity, the inlet jet having an inlet jet orifice; a detection optics assembly located to collect light scattered from particles with the detecting region for producing an output signal indicative of the particles; and an optical barrier complex located to reduce noise as compared to the gain-apertured system without the optical barrier complex for fluid flow rates greater than or equal to about 0.1 cubic feet per minute. The optical barrier complex inhibits laser light from illuminating turbulent eddy currents originating on the interior walls of the inlet jet. The optical barrier complex includes one or more physical apertures, one or more optical stops, or both which are located to prevent laser light from illuminating the eddy currents.

Abstract: An apparatus and method for determining the chemical content of a chemical mechanical planarization (CMP) slurry. A CMP sample cell has windows for passing electromagnetic radiation. Three wavelengths of electromagnetic radiation, one of which is strongly absorbed by said CMP slurry and the other two of which are weakly absorbed by said CMP slurry, are directed through said sample cell to a detector, which processes a signal. A processor utilizes the signal to determine the transmission at each wavelength, then utilizes Beer's law to determine a transmission function for each wavelength, and calculates the wavelength dependent particle transmission for each wavelength using an optical model, to form a system of three equations in three unknowns, which are solved to determine a parameter representative of the chemical content of the CMP slurry.

Abstract: An apparatus and method for determining the chemical content of a chemical mechanical planarization (CMP) slurry. A CMP sample cell has windows for passing electromagnetic radiation. Three wavelengths of electromagnetic radiation, one of which is strongly absorbed by said CMP slurry and the other two of which are weakly absorbed by said CMP slurry, are directed through said sample cell to a detector, which processes a signal. A processor utilizes the signal to determine the transmission at each wavelength, then utilizes Beer's law to determine a transmission function for each wavelength, and calculates the wavelength dependent particle transmission for each wavelength using an optical model, to form a system of three equations in three unknowns, which are solved to determine a parameter representative of the chemical content of the CMP slurry.

Abstract: A sensitive particle distribution probe uses special processing including a modified Twomey/Chahine iterative convergence technique and a specially constructed sample cell to obtain particle size distribution measurements from optically dense slurries, such as the slurries used in the semiconductor industry for chemical mechanical planarization. Spectral transmission data is taken over the spectral range of 0.20-2.5 microns, utilizing specially constructed, chemically resistant sample cells of 50-2000 microns thickness, and miniature, fixed grating, linear detector array spectrometers. At wavelengths greater than one micron, the preferred design utilizes InGaAs linear detector arrays. An ultrasonic disrupter can be employed to breakup harmless soft agglomerates. In addition to direct particle size distribution measurement, the invention described here could be used to detect other fundamental causes of slurry degradation, such as foaming and jelling.

Abstract: A very sensitive particle distribution probe uses special processing including a modified Twomey/Chahine iterative convergence technique and a specially constructed sample cell to obtain particle size distribution measurements from optically dense slurries, such as the slurries used in the semiconductor industry for chemical mechanical planarization. Spectral transmission data is taken over the spectral range of 0.20-2.5 microns, utilizing specially constructed, chemically resistant sample cells of 50-250 microns thickness, and miniature, fixed grating, linear detector array spectrometers. At wavelengths greater than 1 micron, the preferred design utilizes InGaAs linear detector arrays. An ultrasonic disrupter can be employed to breakup harmless soft agglomerates. In addition to direct particle size distribution measurement, the invention described here could be used to detect other fundamental causes of slurry degradation, such as foaming and jelling.

Abstract: Apparatus and method determine the concentration of an individual component, such as water vapor, of a multi-component mixture, such as a gaseous mixture for cooling a nuclear reactor. A hygrometer apparatus includes an infrared source for producing a broadband infrared energy beam that includes a strong water vapor absorption band and a weak water vapor absorption region. The beam is chopped to select infrared pulses. A temporally first pulse has a wavelength in the weakly absorbing region, a temporally second pulse has a wavelength in the strong band and a temporally third pulse has a wavlength in the weakly absorbing region. A fourth reference pulse representing background radiation is interposed in such chopped pulses.

Abstract: The apparatus detects in real time the amplitude and range of certain traent events such as lightning discharges, the arrangement being such that a transient event which is capable of producing a return echo signal initially greater than other return signals is detected and the amplitude and range acquired in a manner which permits recording on moderate speed recording devices. A conventional sample and hold circuit acquires the range and its output gates a peak detector into "on" and "off" modes with the "on" period being centered about the range acquired by the sample and hold circuit. The "on" period is of relatively short duration and, importantly, the output acquired during the "on" period is held by the peak detector circuit until the initiation of the next transmitter pulse. The range output of the sample and hold circuit also is held for a predetermined length of time or until another transient event occurs. The `hold` periods permit the use of moderate speed recording devices.

Abstract: A sensitive particle distribution probe uses special processing including a modified Twomey/Chahine iterative convergence technique and a specially constructed sample cell to obtain particle size distribution measurements from optically dense slurries, such as the slurries used in the semiconductor industry for chemical mechanical planarization. Spectral transmission data is taken over the spectral range of 0.20-2.5 microns, utilizing specially constructed, chemically resistant sample cells of 50-2000 microns thickness, and miniature, fixed grating, linear detector array spectrometers. At wavelengths greater than one micron, the preferred design utilizes InGaAs linear detector arrays. An ultrasonic disrupter can be employed to breakup harmless soft agglomerates. In addition to direct particle size distribution measurement, the invention described here could be used to detect other fundamental causes of slurry degradation, such as foaming and jelling.