Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Other

United States of America as Represented by the Secretary of the Air Force

Carnegie Mellon University

Rosemount Analytical Inc.

Milton S. Gottlieb

Frederick Merk Ryan

Milton S Gottlieb

Thelma J Isaacs

Gerald B Brandt

Nathan T Melamed

John D Feichtner

Fredrick L Schaff

Narsingh Bahadur Singh

Robert Mazelsky

Kenneth B Steinbruegge

Andrea A Price

Richard H Hopkins

Charles H Jones

Frederick M Ryan

James P McHugh

Tom Henningsen

Lyle H Taylor

Donald W Feldman

Louis J Denes

John J Conroy

Anselm Wachtel

Fredrick M Ryan

The present invention is a deployable climate blanket system for regulating temperature of a water surface, including two or more climate blanket secured one to another, each blanket configured with an interior air-filled cavity and a plurality of weights for maintaining the system into a desired position. When use of the blankets is no longer desired, the blankets can be lowered beneath the water surface so as not to interfere with boat traffic or other surface use of the water.

Climate blanket

An electronically agile spectro-polarimetric imager is described in which an acousto-optic tunable spectral filter (AOTF) is located in series with an electronically tunable optical phase modulation plate such that incident radiation will pass through the modulation plate and the AOTF in sequence. This system makes it possible to perform both spectral analysis, complex polarization analysis and object discrimination at video-rates of incident radiation from complex target scenes according to the spectral content and polarization state of the radiation reflected or emitted from the objects within the scene, regardless of the polarization state of the incident radiation. Embodiments for analyzing incident radiation of various wavelengths are provided.

Spectro-polarimetric imager

Acousto-optical devices utilize crystals of a novel material thallium arsenic sulfide (Tl.sub.3 AsS.sub.3) grown from a melt. A Tl.sub.3 AsS.sub.3 crystal is cut and parallel faces are prepared and polished. A piezoelectric transducer connected to an RF generator is placed on the acoustic face to generate sound waves. The light is directed through the optical face of the crystal and interacts with the acoustic waves. These devices may be used in signal processing, spectrum analyzing, spectroscopic, liquid analyzing and spectral imaging systems.

Acousto-optic devices utilizing thallium arsenic sulfide (T1AsS.sub.3)

The optical device can examine a spectrum at low resolution and subsequently choose a portion of that spectrum to be examined at higher resolution, using a single detector array for both spectra. The latter spectrum can be chosen to be arbitrarily anywhere within the low resolution spectrum. The device comprises a source of input light, a wedged shaped dispersive device, a first reflective mirror, a second reflective mirror, a RF generator connected to the dispersive device, and a detector array. In operation, the dispersive device provides a low dispersion spectrum in the zero order light when the source of light is impinged upon it. When the RF generator is turned on, a second spectrum which is diffracted is obtained. This will be the high resolution spectrum. By operating near 100% diffraction efficiency, it is possible to switch from one spectrum to the other. By adjusting the RF frequency the band center of the high resolution spectrum can be varied to fall anywhere within the low resolution spectrum. Since the two spectra will not normally physically fall in the same place, the zero order spectrum is reflected by a first mirror onto the detector array and the diffracted spectrum is reflected by a second mirror on to the detector array so that the two spectra overlay and fall in the same detector array.

Electrically controlled multiple dispersion (zoom) device

A source of broad-band and/or narrow band optical radiation is detected and identified by apparatus including a pair of acousto-optical tunable filters which diffract from orthogonally polarized components of the optical radiation, a diffracted ordinary polarized beam and diffracted extraordinary beam, respectively. Undiffracted polarized radiation from the two AOTFs is combined and directed to a first detector which may comprise a small array such as a quadrant array. The diffracted ordinary and extraordinary polarized beams are directed to a second detector which is preferably a single large imaging array. A signal processor uses signals from the first detector generated by the undiffracted beams to detect the presence of the source, and polarized spectral signals from the large imaging array to identify the source of the radiation . A control unit generates radio frequency signals which can be rapidly varied in frequency to control wavelength of the polarized beams diffracted by the AOTFs. These radio frequency (rf) signals may be applied simultaneously, with or without amplitude modulation, or sequentially, to the AOTFs, and may be of the same or different frequencies. The rf drive may be withheld from the AOTFs to maximize the undiffracted beams for maximum range detection.

Acousto-optic tunable filter apparatus and method for detecting and

A remote gas measuring apparatus and method utilizes the optical absorption line characteristics to determine an amount of gas of interest as may exist in an area under study. The remote gas measuring apparatus includes a source of electromagnetic radiation that can be projected toward the area in question and a light collecting arrangement. The light signal received is coupled to a fast light switch modulator which modulates the light signal to a first frequency. A second modulating arrangement modulates the light signal to a second frequency and includes a birefringent etalon device having a periodic spacing equal to the periodicity of the absorption lines of the gas of interest. The second modulating means is further effective such that, when an electric field is applied thereto the transmission spectra associated with the light signal is shifted between spectra which coincide with the absorption lines and spectra which fall between the absorption lines. The light signal from the etalon device is then conditioned and input to a detector configuration which distinguishes between the light signal at the first frequency and the light signal at the second frequency in order to determine at least a quantity of the gas of interest.

Method and apparatus for remotely and portably measuring a gas of

A gas analyzer arrangement for detecting the presence or quantity of a gas of interest includes a source of electromagnetic radiation for directing a light beam through a light conditioning device such that the light beam is collimated into a parallel beam of light. The conditioned light beam is then directed through a gas sample cell which contains a sample of the gas of interest. The gas of interest has associated therewith, vibrational rotational absorption lines specific to that gas and which are effective for altering the light beam according to the absorption characteristics thereof. The altered light beam is then directed to a birefringent etalon device which has been sized specifically to match those absorption lines of the gas of interest. An electro-optical modulator device associated with the birefringent etalon modulates the absorption lines between the transmission spectra maxima and a point between the transmission spectra maxima so that an absorption ratio can be utilized to determine the presence or quantity of the gas of interest.

Method and arrangement for measuring the optical absorptions of gaseous

A method and apparatus for increasing the angular aperture of an acousto-optic device employing an acoustic zone plate positioned on an acoustic input face of an acousto-optic device. The angular spread of acoustic energy within the acousto-optic device is increased over the angular spread obtainable with a single transducer of the same length; thus providing an increased angular aperture for the resultant acousto-optic device.

Method and apparatus for increasing the angular aperture of an

Disclosed is a crystal 1 of thallium arsenic selenide, thallium arsenic sulfide, thallium vanadium sulfide, thallium phosphorous selenide, lead halide, cadmium sulfide, cadmium selenide, cadmium tin arsenide, cadmium germanium arsenide, indium phosphoride, indium arsenide, or mixtures thereof, doped with a precious metal in an amount of about 25 ppm up to the solubility limit of a precious metal in the crystal. The crystal is useful in nonlinear optical devices, acousto-optical devices, piezoelectric devices, and other types of optical and acoustic devices.

Precious metal doped crystals for hardening of the crystals

A method and apparatus for increasing the angular aperture of an acousto-optic dispersive light filter in which acoustic frequencies of differing frequencies are launched into a crystal at differing angles to each other. Input light phase matches with corresponding ones of the acoustic frequencies so that the angular aperture is enlarged.

Method and apparatus for improving the angular aperture of an aodlf

An acousto-optic tunable filter configuration and a method for the operation thereof, whereby the tuning range is extended. A non-collinear acousto-optic tunable filter crystal has a first transducer bonded to one transducer face of the crystal and a single transducer bonded on the opposite crystal face which crystal face is cut so as to be parallel to the first transducer. The first transducer operates at a center frequency f.sub.1 and the second transducer operates at a center frequency f.sub.2. By launching acoustic waves having a center frequency f.sub.1 into the crystal from the crystal's first side acoustic waves propagate in a first direction such that the interaction of the acoustic wave with the light results in the absorption of a phonon. Acoustic waves having a center frequency f.sub.2 are launched into the crystal from the crystal's second side and propagate in a second direction which is anti-parallel to the first direction such that the interaction with the light by the second series of acoustic waves results in the stimulated emission of a phonon.

Acousto-optic tunable filter with two acoustic channels

The invention is directed to an acousto-optic dispersive light analyzer (AODLF) which is an electronically adjustable spectroscopic device capable of instantaneously monitoring many wavelengths with a fixed drive frequency. The AODLF has about a one octave range, whose center is selected by changing the RF. The resolution of the AODLF in the infrared is several thousand, and it is electronically adjustable. The acousto-optic device according to this invention is particularly useful for the detection and analysis of short light pulses. An additional capability of the AODLF is its operation in a derivative mode for enhanced SNR of coherence detection in the presence of a high incoherent background by imposing a very small frequency modulation on the RF applied to the AODLF. Then by phase locking each of the detector element signals at first the fundamental and then the first harmonic of the FM, the first and second spectrum derivatives of each resolution element can be observed.

Acousto-optic dispersive light filter

The invention is directed to an acousto-optic dispersive light analyzer (AODLF) which is an electronically adjustable spectroscopic device capable of instantaneously monitoring many wavelengths with a fixed drive frequency. The AODLF has about a one octave range, whose center is selected by changing the RF. The resolution of the AODLF in the infrared is several thousand, and it is electronically adjustable. The acousto-optic device according to this invention is particularly useful for the detection and analysis of short light pulses.

An improved acousto-optic tunable filter infrared analyzer system useable in a variety of industrial and commercial combustion control applications includes an acousto-optic tunable filter having a crystalline material selected from the group consisting of mercurous chloride, mercurous bromide and mercurous iodide. Selectively polarized infrared radiation is passed at a predetermined plane of incidence to the crystal axis, which plane contains both the (110) and (001) axes. The system relies upon a narrow band pass tunable acousto-optic filter which is selectively tuned by predetermined rf frequency signals to selectively transmit the narrow band pass of interest which corresponds to a specific molecular species for identification and analysis. The system includes a microcomputer and associated memory function to measure and compare detected signals from an infrared detector which converts the filtered infrared signal to an electrical signal. The memory provides control signals for the computer and for controlling the sequence and frequency of rf energy applied to tune the filter. In this way, the near to far range infrared can be analyzed for absorption bands corresponding to predetermined molecular species such as combustion product gases, and a feedback signal generated to control the combustion process.

Acousto-optic tunable filter

The invention relates to a method and an apparatus for enlarging the spectral range of an acousto-optic tunable filter by extending the operation of the transducer structure to its third harmonic. The transducer structure consists of a plurality of individual transducer elements in electrical communication through a switching network which modifies the total capacitance of the transducer structure to provide a satisfactory impedance match at both the fundamental and the third harmonic.

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Churchill, PA, United States of America

Milton S Gottlieb