Alliedsignal Inc.

Janpu Hou

Scott Moore Zimmerman

Karl Wayne Beeson

Devlin M Gualtieri

William Ross Rapoport

John C Schweyen

Herman Van De Vaart

Robert C Morris

Stephen M Emo

Jerry W Kuper

Terrance R Kinney

Waltraud Rosalie Unger

Herman VandeVaart

An optical illumination system comprising a waveguide that accepts light generated by a light source and transmits the light via total internal reflection. Attached on one face of the waveguide is an array of microprisms, with each microprism having an light input surface, a light output surface and at least one sidewall which is tilted at an angle from the direction normal to the surface of the waveguide and further comprising at least two planar faces such that light escapes from the waveguide, reflects off the tilted sidewalls and emerges from the microprism as a spatially directed light source. An array of microlenses may be positioned to accept the output of the microprisms so that the light exiting from the microlenses is a substantially collimated light source. The optical illumination system is advantageous for any application that requires a non diffuse or substantially collimated light source that is both energy efficient and contained in a low profile assembly.

Illumination system employing an array of multi-faceted microprisms

The light output of a back-coupled illumination system is improved by recycling reflected and misdirected light rays. A reflector at the light source and an array of microprisms having reflective elements therebetween efficiently redirect errant light rays to increase the total available light output and improve efficiency. Both specular and diffuse reflective materials may be used in combination to enhance light output.

Back-coupled illumination system with light recycling

An optical illumination system comprising a waveguide that accepts light generated by a diffuse light source and transmits the light via total internal reflection. Attached on one face of the waveguide is an array of microprisms, with each microprism having an light input surface parallel to a light output surface and at least two sidewalls tilted at an angle from the direction normal to the surface of the waveguide such that light escapes from the waveguide, reflects off the tilted sidewalls and emerges from the microprism as a spatially directed light source. An array of microlenses may be positioned to accept the output of the microprisms so that the light exiting from the microlenses is a substantially collimated light source. The optical illumination system is advantageous for any application that requires a non diffuse or substantailly collimated that is both energy efficient and contained in a low profile assembly.

Illumination system employing an array of microprisms

A birefringent bias is provided to an optical sensor by the addition of one or more single birefringent elements where the total birefringence-length product remains within the accepted tolerances of current devices. The bias provided by two or more elements is such that where each element has a birefringence, a dB/dT and a coefficient of thermal expansion term, the elements are arranged in tandem so that the combined birefringence terms equal the required birefringence bias and the dB/dT and coefficient of thermal expansion terms effectively cancel.

Birefringent-biased sensor having temperature compensation

A cladded birefringent pressure sensor for use in a pressure-sensing system. The sensor is a single composite plate consisting of two plates each with different indices of refraction. One surface of the sensor is exposed to the environmental pressure under measurement. A collimated broad band light source is transmitted via a fiber optic cable, a polarizer and a birefringent bias element which transmits a wavelength/polarization component of light through the sensor. An external force applied to the sensor adds a stress-induced component to the polarized lightwave. The lightwave exits the sensor and is captured by a second polarizer producing a modulated light spectrum. A focusing element collects the light and transmits it down another fiber optic cable. The cable transmits the light to an opto-electronic interface where the fringe pattern is extracted and a computer compatible signal is generated for a CPU. The CPU performs a Fourier transform on the fringe pattern, where the phase term for a selected frequency is the measure of the externally applied pressure on the sensor.

System to determine environmental pressure and birefringent-biased

An integrated optical temperature and pressure sensor system that is birefringently biased. A broad band light source is transmitted via a fiber optic cable having a splitter, a collimator and a polarizer to a first birefringent bias element. The first birefringent element has a partially reflective coating to reflect back a portion of the light signal to the first polarizer to yield a first reflective modulated light that consists of temperature information irrespective of external forces. The non-reflected light continues to a second birefringent bias element. The second birefringent crystal provides additional birefringent bias to the light wave before the light wave enters an isotropic pressure sensor media. An external pressure applied to the sensor causes the light to experience stress-induced birefringence. The sensor comprises a highly reflective surface which redirects the light back through the sensor, both bias crystals and the polarizer to yield a second reflective modulated light spectrum. The splitter which directs a combined light spectrum comprising a portion of each reflected light spectrum to an opto-electronic interface where the intensity vs. wavelength signal is extracted by a CPU. The CPU performs a Fourier transform on the signal to reveal a first phase term at a selected frequency that relates to the temperature of the system and a second phase term at a different selected frequency that relates to the temperature of the system and the externally applied pressure on the sensor. Subtracting out the temperature term from the temperature and pressure term provides the pressure value.

Integrated birefringent-biased pressure and temperature sensor system

An optical illumination system comprising a waveguide that accepts light generated by a diffuse light source and transmits the light via total internal reflection. Attached on one face of the waveguide is an array of microprisms, with each microprism having an light input surface parallel to a light output surface and at least two sidewalls tilted at an angle from the direction normal to the surface of the waveguide such that light escapes from the waveguide, reflects off the tilted sidewalls and emerges from the microprism as a spatially directed light source. An array of microlenses may be positioned to accept the output of the microprisms so that the light exiting from the microlenses is a substantially collimated light source. The optical illumination system is advantageous for any application that requires a non diffuse or substantially collimated that is both energy efficient and contained in a low profile assembly.

A sensor for use in an optic system to detect current conditions in an environment. The sensor has a crystal member with a first waveguide extending from a top surface and a second waveguide extending from a bottom surface of a core member. Polarized light waves from a source are simultaneously communicated to the first and second waveguides. A first pressure is communicated to the top surface of the crystal member and an unknown pressure corresponding to the pressure of the environment is communicated to the bottom surface of the crystal member. The first pressure and the unknown pressure develop a pressure differential which acts on the crystal member to deform the first and second waveguides. The deformation of the first and second waveguides modifies the polarized light waves to create first and second output waves which are communicated to an optical interface where differences therebetween are extracted. The differences are analyzed by a computer to identify the current pressure and temperature of the environment.

Optic sensor for determining environmental conditions

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. A fiber optic cable connected to the second linear polarizing element carries the modulated light spectrum to an opto-electronic interface where the fringe pattern is extracted and a computer compatible signal is generated for a CPU to accurately indicate current environmental temperature conditions up to 1000.degree. C. experienced by the single crystal plate crystal in the birefringent element.

Fringe pattern analysis of a birefringent modified spectrum to determine

This invention provides birefringent optical waveguide structures of crystalline aluminum garnet of a high refractive index which are clad with crystalline aluminum garnet of a lower refractive index. Due to predetermined lattice mismatch between garnet substrate and cladding layer, strain is induced which causes a stress with resultant birefringence in the waveguide layer. When linearly polarized light enters such stressed waveguide in certain orientations, the linear polarization will be preserved by the stress-induced birefringence. These birefringent clad waveguides can be in the form of slabs, channels, ribs, or any of the typical optical waveguide structures. They are useful at high temperature.

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Bridgewater, NJ, United States of America

Janpu Hou