The Boeing Company

Eospace Inc.

Gregory L Abbas

Michael De La Chapelle

Edward Joseph Vertatschitsch

Charles R Porter

J Doyle McClure

An optical modulator has a continuous wave laser input, an RF input, a bias and dither input and an output. A photodiode connected to an output tap produces a voltage that is amplified. Noise is removed from the amplified output. A spread-spectrum dither harmonic is generated and supplied to a multiplier with the amplified and filtered feedback and is used to create a DC bias. A spread-spectrum dither is created and added to the DC bias. Spread spectrum dither and bias both are applied to the bias input of optical modulator. The bias and spread spectrum dither controller is usable with other non-optical modulators and other electronic devices.

Spread-spectrum bias control

An optical sensing system for sensing the temperature at a first location, including: electro-optical unit for producing a modulated optical signal and a light guide unit for receiving and transmitting the modulated optical signal along an optical path. The optical system further includes temperature sensing fiber which receives and guides the modulated optical signal along a temperature sensing optical path. One portion of the modulated optical signal serves as a reference optical signal and another portion of the modulated optical signal serves as a target optical signal. The optical sensor system also has a transducing unit, which receives the reference optical signal, the target optical signal having first and second time delays with respect to a chirped rf signal from the electro-optical unit. The transducing unit produces a multi-frequency electrical signal which includes a first frequency corresponding to the first time delay a second frequency corresponding to the second time delay. The optical sensor system further has a temperature detecting means coupled to the output of the transducing unit which processes the multi-frequency signal and determines a difference frequency corresponding to the temperature at the first location.

Temperature sensing optical system

An optical sensing system with a rotation sensor head for sensing the rotation of a rotatable object while simultaneously sensing the position of a displaceable object with a position sensor head. An electro-optical unit outputs a modulated optical signal and a chirped rf signal. The envelope of the modulated optical signal has a phase that has a known relation to the phase of the chirped rf signal. The electro-optical unit is coupled to a light guide element and receives and transmits the modulated optical signal along an optical path for reflection off a disk secured to the rotatable object in order to provide a rotation sensing optical signal. A transducing unit receives the rf signal at one input and has another input optically coupled to receive the rotation sensing optical signal while simultaneously receiving position sensing optical signals from the position sensor heads. The transducing unit produces a multi-frequency electrical signal which includes first and second frequencies, the first frequency corresponding to the rotation sensor location and the difference between the first and second frequencies corresponding to the rotation rate of the rotatable object. A rotation detecting unit coupled to the output of the transducing unit processes the multi-frequency signal in order to determine the difference frequency corresponding to the rotation rate of the rotatable object.

High accuracy optical rotation sensing system

An optical position sensing system for sensing the position of a displaceable element. An electro-optical unit outputs a modulated optical signal and a chirped rf signal. The envelope of the modulated optical signal has a phase that has a known relation to the phase of the chirped rf signal. The electro-optical unit is coupled to a light guide element and receives and transmits the modulated optical signal along an optical path for reflection off a surface of the displaceable element in order to provide a position sensing optical signal. A reference reflecting element is disposed in the optical path upstream of the displaceable element for partially reflecting the transmitted modulated optical signal in order to provide a reference optical signal. A transducing unit receives the rf signal at one input and has another input optically coupled for receiving the position sensing optical signal and the reference optical signal which have, respectively, first and second time delays with respect to the chirped rf signal. The transducing unit produces a multi-frequency electrical signal which includes first and second frequencies corresponding to the first and second time delays, respectively. A position detecting unit coupled to the output of the transducing unit processes the multi-frequency signal in order to determine a difference frequency corresponding to the difference between the first and second frequencies and representing the position of the displaceable element.

Growing community of inventors

Fall City, WA, United States of America

Gregory L Abbas