Abstract: The disclosed technology may include systems, methods, and apparatus for optical measurements. A method is provided that includes receiving, by first and second Extrinsic Fabry-Perot Interferometer (EFPI) sensors, respective portions of interrogation light. The first EFPI sensor is responsive to a measurement stimulus and both the first EFPI sensor and the second EFPI sensor are responsive to a common mode stimulus. The method includes detecting a measurement signal and a first common-mode signal responsive to receiving altered interrogation light from the first EFPI sensor, the measurement signal corresponding to the measurement stimulus. The method includes detecting a second common mode signal responsive to receiving altered light from the second EFPI sensor.

Abstract: Certain implementations of the disclosed technology may include Fabry-Perot Interferometer (FPI)-based sensors systems and methods for measuring a desired stimulus. In accordance with an example implementation of the disclosed technology, a method is provided for receiving, by a Fabry-Perot Interferometer (FPI) sensor, first interrogation light having a first wavelength and second interrogation light having a second wavelength. The FPI sensor is configured to alter the received first interrogation light and the second interrogation light responsive to a measurement stimulus. The method includes detecting, by a first optical detector, a measurement signal responsive to receiving the altered first interrogation light and the altered second interrogation light from the FPI sensor, the measurement signal corresponding to the measurement stimulus. The method includes producing a measurement output signal, the measurement output signal representing an intensity of the measurement signal.

Abstract: A optical sensor assembly is disclosed that includes a sensor diaphragm configured to deflect responsive to an applied stimulus. The sensor assembly includes a first Extrinsic Fabry-Perot Interferometer (EFPI) having a first optical cavity in communication with at least a portion of the sensor diaphragm, the first EFPI is configured to interact with light to produce a combined measurement light signal and a first common-mode light signal, the measurement light signal corresponding to the applied stimulus. The sensor assembly also includes a second EFPI having a second optical cavity, the second EFPI is configured to interact with light to produce a second common mode light signal for error correction. The sensor assembly may further include a sensing optical fiber in communication with the first EFPI; a reference optical fiber in communication with the second EFPI; and a glass header configured to support the sensing optical fiber and the reference optical fiber.

Abstract: Certain example implementations of the disclosed technology include an optical-interferometer sensor assembly for measuring pressure or acceleration. The sensor assembly includes a diaphragm configured to deflect responsive to an applied stimulus, a diaphragm support structure in communication with the diaphragm, a sensing optical interferometer having a first optical cavity in communication with at least a portion of the diaphragm and the diaphragm support structure, and a reference optical interferometer having a second optical cavity in communication with the diaphragm support structure. The sensor assembly can include a sensing optical fiber in communication with the sensing optical interferometer and a reference optical fiber in communication with the reference optical interferometer. The sensor assembly can include a housing in communication with the diaphragm and the diaphragm support structure, and configured to reduce a thermal expansion mismatch in the sensor assembly.

Abstract: Certain implementations of the disclosed technology may include Fabry-Perot Interferometer (FPI)-based sensors systems and methods for measuring a desired stimulus. In accordance with an example implementation of the disclosed technology, a method is provided for receiving, by a Fabry-Perot Interferometer (FPI) sensor, first interrogation light having a first wavelength and second interrogation light having a second wavelength. The FPI sensor is configured to alter the received first interrogation light and the second interrogation light responsive to a measurement stimulus. The method includes detecting, by a first optical detector, a measurement signal responsive to receiving the altered first interrogation light and the altered second interrogation light from the FPI sensor, the measurement signal corresponding to the measurement stimulus. The method includes producing a measurement output signal, the measurement output signal representing an intensity of the measurement signal.

Abstract: The disclosed technology may include systems, methods, and apparatus for optical measurements. A method is provided that includes receiving, by first and second Extrinsic Fabry-Perot Interferometer (EFPI) sensors, respective portions of interrogation light. The first EFPI sensor is responsive to a measurement stimulus and both the first EFPI sensor and the second EFPI sensor are responsive to a common mode stimulus. The method includes detecting a measurement signal and a first common-mode signal responsive to receiving altered interrogation light from the first EFPI sensor, the measurement signal corresponding to the measurement stimulus. The method includes detecting a second common mode signal responsive to receiving altered light from the second EFPI sensor.

Abstract: A optical sensor assembly is disclosed that includes a sensor diaphragm configured to deflect responsive to an applied stimulus. The sensor assembly includes a first Extrinsic Fabry-Perot Interferometer (EFPI) having a first optical cavity in communication with at least a portion of the sensor diaphragm, the first EFPI is configured to interact with light to produce a combined measurement light signal and a first common-mode light signal, the measurement light signal corresponding to the applied stimulus. The sensor assembly also includes a second EFPI having a second optical cavity, the second EFPI is configured to interact with light to produce a second common mode light signal for error correction. The sensor assembly may further include a sensing optical fiber in communication with the first EFPI; a reference optical fiber in communication with the second EFPI; and a glass header configured to support the sensing optical fiber and the reference optical fiber.

Abstract: Certain example implementations of the disclosed technology include an optical-interferometer sensor assembly for measuring pressure or acceleration. The sensor assembly includes a diaphragm configured to deflect responsive to an applied stimulus, a diaphragm support structure in communication with the diaphragm, a sensing optical interferometer having a first optical cavity in communication with at least a portion of the diaphragm and the diaphragm support structure, and a reference optical interferometer having a second optical cavity in communication with the diaphragm support structure. The sensor assembly can include a sensing optical fiber in communication with the sensing optical interferometer and a reference optical fiber in communication with the reference optical interferometer. The sensor assembly can include a housing in communication with the diaphragm and the diaphragm support structure, and configured to reduce a thermal expansion mismatch in the sensor assembly.

Abstract: An apparatus and method for optically detecting whether a substance is present at an inspection site on a base material based on light reflected from the inspection site. A light module generates light of a first wavelength and light of a second wavelength. A first optical transmission medium directs the light of the first wavelength and the light of the second wavelength to the inspection site. A photodetector receives light reflected from the inspection site and generates a reflection signal corresponding to the reflected light. A second optical transmission medium directs the reflected light from the inspection site to the photodetector. A control module has an input for receiving the reflection signal.

Abstract: An apparatus and method for optically detecting whether a substance is present at an inspection site on a base material based on light reflected from the inspection site. A light module generates light of a first wavelength and light of a second wavelength. A first optical transmission medium directs the light of the first wavelength and the light of the second wavelength to the inspection site. A photodetector receives light reflected from the inspection site and generates a reflection signal corresponding to the reflected light. A second optical transmission medium directs the reflected light from the inspection site to the photodetector. A control module has an input for receiving the reflection signal.

Abstract: The change in the circular birefringence of a sample is measured by passing a light beam comprised of a left circularly polarized (LCP) wave and a right circularly polarized (RCP) wave through a sample and measuring the change in the phase difference between the RCP and LCP waves.

Abstract: The change in the circular birefringence of a sample is measured by passing a light beam comprised of a left circularly polarized (LCP) wave and a right circularly polarized (RCP) wave through a sample and measuring the change in the phase difference between the RCP and LCP waves.

Abstract: A gyroscope for detecting angular velocity includes a closed housing having a plurality of nested layers of superconducting material with the majority of these nested layers being divided so as to disrupt the path of superelectrons traveling within the superconducting material of these nested layers. These nested layers of superconducting material shield the interior of the closed housing from external magnetic fields and prevent the generation of a London moment field within the closed housing when the housing is rotated. A gyroscope sensor is securely mounted within the closed housing for detecting the rotation of the housing. The gyroscope sensor is comprised of a gyroscope sensor block having a plurality of sensor device faces where a corresponding plurality of gyroscope sensor devices are situated. Each of the plurality of gyroscope sensor devices is comprised of a multilayer superconducting thin film structure.

Abstract: A quantum well bias mirror 30 provides phase modulation to two counter-propagating beams in a ring laser gyroscope so as to reduce or eliminate the effects of lock-in. The phase modulation is caused by inducing an index of refraction change, known as the Franz-Keldysh effect, in the quantum well bias mirror 30 by applying a varying electric field across a quantum well structure in the mirror 30. The quantum well bias mirror 30 is comprised of a substrate 32 coated with a plurality of dielectric layers 36,38 of alternately high and low refractive indices, respectively, which in turn are coated with a quantum well filter layer 34. The dielectric layers 36,38 are adjusted to provide maximum reflectivity of the counter-propagating beams. The quantum well filter layer 34 is adjusted to cause a reflection from its top surface when there is no electric field present and to cause a reflection from the top of the dielectric layers 36,38 when an electric field is present.