Faz Technology Limited

Input/output, Inc.

Optics11 Faz Limited

I/o of Austin, Inc.

Ion Geophysical Corporation

Roger Maher

John O'Dowd

Richard A Johnson

Ben William Jones

Scott T Dupuie

Mark E Burchfield

Michael L Abrams

Tom Farrell

Burton A Devolk

Martin Farnan

Jeffrey Blackburn

Mauricio A Zavaleta

Franklin W Mayo

John Dunne

Frank Mayo

Devrez Mehmet Karabacak

Selwan K Ibrahim

Mauricio Zavaleta

Vivian Bessler

Lymperis Voudouris

James Broseghini

Ibrahim Selwan

Ben Jones

Jeffrey A Blackburn

The present invention provides a method for measuring an optical sensor system comprising an array of intrinsic fiber optic sensors at an interrogator comprising an optical source and an optical detector. The method comprises the steps of emitting an optical signal to an array of intrinsic fiber optic sensors; detecting optical responses to the emitted signal from the sensors; associating each detected optical response with an individual sensor by determining within which region among a plurality of detection regions assigned to the individual sensors the optical response is detected wherein each detection region corresponds to a wavelength range in the bandwidth of the optical sensor system; and performing signal processing on each optical response to measure the value of the physical parameter detected by its associated sensor. A calibration of the detection region assigned to each sensor is performed at predetermined intervals.

System and method for interrogating an intrinsic fiber optic sensor

The invention provides a dynamically swept tunable laser system and method for measuring sensor characteristics obtained from an array of optical sensors comprising means for dividing the total wavelength sweep of the laser into different regions in any particular order where each region contains single or multiple contiguous sweep segments and where each sweep segment is referenced by a start and a stop reference and can have different lengths compared to the other sweep segments. The sensor characteristics are determined from each region swept by the tunable laser. The invention provides for the tunable laser to be adapted to operate in a quasi-continuous mode to select segments in any order. The relative sweep rates of regions can be changed such that some regions can be swept more times than other regions.

System and method for dynamically sweeping a tunable laser

The invention provides a system and a method for wavelength referencing and polarization mitigation. An optical wavelength tunable laser source is swept in a number of contiguous, overlapping sweep segments. A coarse reference wavelength section produces a reference signal that defines at least one absolute wavelength within a sweep segment. A fine wavelength reference section produces a periodic wavelength reference signal that defines a plurality of equidistant wavelengths within each sweep segment with an indeterminate offset relative to the absolute wavelength(s) of the coarse reference wavelength section. The free spectral range of the fine wavelength reference section is smaller than the spacing between subsequent absolute reference wavelengths of the coarse reference wavelength section. This arrangement allows reducing the minimum required overlap between contiguous sweep segments.

System and method to compensate for frequency distortions and polarization induced effects in optical systems

A system for acquiring environmental information measurements. The 5 system () utilize a sensor, () a front-end circuit, () a loop filter (), a switch controller (), and a reduced-order loop control circuit to provide reliable data measurements while providing robust system behavior. The system further includes a sensor simulator () for simulating the operation of the sensor () and testing the operation of the front-end circuit () and the loop filter ().

Sensor

A method and apparatus for measuring and compensating for stray capacitance of a micro-machined sensor of an accelerometer system is disclosed. Stray capacitance differences between a top plate and a sensing element and between a bottom plate and the sensing element degrade accelerometer performance if not compensated for. Measurement of stray capacitance difference is achieved by operating the accelerometer in two calibration phases and measuring the steady-state output voltage in each of the two phases. In calibration phase 1, no force is applied to the sensor during clock intervals 1-4. In calibration phase 2, a dummy force up is applied and then a dummy force down is applied during those intervals 1-4. The difference in the output voltage of the two calibration phases is representative of the difference in stray capacitance of the sensor. Capacitance is added to the top or bottom plates in an amount proportional to the measured stray capacitance. The procedure is repeated until the voltage difference of the two calibration phases is zeroed, which is indicative that the inherent stray capacitance has been zeroed.

Method and apparatus for calibration of stray capacitance mismatch in a

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Roger Maher