Abstract: A self-calibrating optical reflectance probe system having an illuminant light source to illuminate a sample material, optical pickup means to collect reflected light from the sample material, and an articulated white reference reflection standard for illuminant reference to provide a system capable of accurately measuring optical reflectance and automated verification of proper operation. The probe system preferably employs an uncomplicated mount using a single pipe fitting and clamp.

Abstract: A self-calibrating optical reflectance probe system having an illuminant light source to illuminate a sample material, optical pickup means to collect reflected light from the sample material, and an articulated white reference reflection standard for illuminant reference to provide a system capable of accurately measuring optical reflectance and automated verification of proper operation. The probe system preferably employs an uncomplicated mount using a single pipe fitting and clamp.

Abstract: A wideband optical micro-spectrometer system for detecting the intensity of light as a function of wavelength. The device employs multiple optical micro-spectrometers generating adjacent spectra mounted onto a single photodetector array and digital processing techniques to generate a continuous wide spectrum from the narrower spectrums generated by the optical micro-spectrometers. Optical micro-spectrometers generating non-adjacent spectra could also be employed to produce spectral data for predetermined non-adjacent spectral ranges. System reliability is improved and maintenance reduced with the use of pre-aligned optical micro-spectrometers. Thereby, a device is created which has the spectral range of larger spectrometers having a much reduced physical size, increased system reliability and reduced maintenance requirements.

Abstract: An optical sensor unit is provided which is capable of being manufactured as a small sensor package as a result of a novel housing used to align a sensing element with respect to an incoming optical signal, such as a beam of light generated by an LED or laser. An arcuate internal passage within the housing defines a reflective optical waveguide which is capable of redirecting the light as it travels through the housing, such that mirrors, prisms and collimating lenses are not required. Furthermore, the optical waveguide is an improvement over the use of optical fibers which are bent to form a waveguide, in that losses and mechanical failures associated with sharp bends in optical fibers are avoided.

Abstract: A process for analyzing a spectral signal generated by a birefringent element and transmitted to an array. An output spectral signal emanating from the array is converted from an analog to a digital signal to establish a reference wave form which has a dominant frequency after the birefringent element is exposed to a known temperature. Thereafter, a current wave form is generated from the output spectral signal emanating from the array. A phase and frequency relationship is obtained by cross correlating the current wave form and the reference wave form. The dominant frequency for the phase and frequency relationship is obtained by Fast Fourier Transformation. Thereafter, the dominant frequency for the phase and frequency relationship of the current wave form is compared with the dominant frequency for the reference wave form to determine a temperature range.

Abstract: A sensor for use in an optical temperature detector system having a birefringent element made of a single crystal metal oxide plate. A broad band light spectrum is transmitted through a first linear polarizing element to create a linearly polarized wave. The linearly polarized wave on passing through the single crystal metal oxide plate decomposes into first and second orthogonally polarized waves. Propagation of the linearly polarized wave through the birefringent single crystal metal oxide plate introduces a temperature dependent phase shift between the two waves. Thereafter, a second linear polarizer combines the first and second orthogonally polarized waves to create a modulated light spectrum having a fringe pattern, the fringe pattern being a function of the current temperature experienced by said birefringent element.

Abstract: An arrangement and technique for decoding optical wave division multiplexed Manchester Gray coded serial binary signals is disclosed wherein synchronization information is utilized to establish a preferred timing of bits of data and then the incoming signal is monitored to detect data bits appearing within prescribed bounds of permissible timing variation from the preferred timing. When a bit is detected within these prescribed bounds, it is reset to appear at the time at which it should have occurred according to the preferred timing.

Abstract: A light off detecting arrangement for sensing the presence of a flame in a region such as the afterburner of a turbine engine is disclosed. An optical focusing device such as a lens or mirror is located near a quartz window adjacent the afterburner for concentrating electromagnetic radiation emanating from the region. An optical (fiber optic) pathway receives the concentrated electromagnetic radiation from the optical focusing device and conveys that radiation thru the optic filters to an opto-electrical converter for converting incident electromagnetic radiation to electrical signals. A frequency selective optical device such as an infrared filter is interposed between the optical focusing device and the opto-electrical converter for insuring that a preselected portion only of the electromagnetic radiation emanating from the region is converted to electrical signals.

Abstract: An optically controlled fluid powered actuator is disclosed and includes a primary fluid valve positioning transducer which responds to optical binary coded control words to position a fluid. The actuator has a pair of opposed stacks of piezoelectric elements with the relative length of the piezoelectric elements in each stack being in the same ratios as the relative weights of bits in the control words. There are two sets of optically actuated electrical switches each responsive to control words to energize corresponding ones of the piezoelectric elements in an associated stack of elements. A first class lever has one end coupled to a controlling portion of a fluid valve and the other end interposed between the stacks of piezoelectric elements so that the lever can translate motion of elements in a piezoelectric stack into fluid valve actuation. A fluid powered electrical generator provides the sole source of electrical energy for the piezoelectric elements.

Abstract: A method of encoding and decoding a binary modulated light spectrum to recover encoded intelligence. The method enables reliable and accurate decoding of wave division multiplexed data. The method incorporates a step of encoding data and a step of decoding the data which employs a photo-detector array. This method of encoding and decoding data compensates for variations in signal level, spectral position and spectral width with no degradation in reconstructed data.

Abstract: An optical spectral analyzer (10) for receiving an input beam (30) through a multi-mode optic fiber (28). The input or beam (30) has a predetermined spectral band width. The random individual spectral components of the beam (30) are dispersed by a grating (40) to generate a spectrum (42, 42' . . . 42.sup.N). A detector (52) senses the magnitude of the elements in a reflected focused spectrum (50, 50' . . . 50.sup.N) to recover the information placed on the optic fiber (28) at a remote location by a spectrum encoding device.

Abstract: An electro-optic speed sensor for sensing the speed of rotation of a rotating sending unit which includes an optical switch transducer for sensing disturbances in a magnetic field caused by the passage of a rotating magnetic sending wheel on the rotating member. The optical switch transducer uses a Faraday material and provides its signal by rotating the polarity of polarized light from a first source of light having a first bandwidth while allowing a second source of light having a second bandwidth to pass through unaffected. The first and second sources of light are thereafter, reflected within the transducer. The disturbances in the magnetic field generate an optical signal resulting from changes in the Faraday rotation. A photodetector receives the light from the first source to develop an operational signal corresponding to the speed of rotation of the rotating member and light from the second source to check on the continuity of the sensor system.

Abstract: The invention is a temperature sensor which uses the variation in the critical angle between two optically transparent media, at least one of which has an index of refraction variable as a function of temperature, to variably refract and reflect portions of a spectrum incident on the junction of the media at angles less than and greater than the critical angle to produce an optical signal variable as a function of temperature.