Abstract: Pixel arrangements in time-of-flight sensors are presented that include sensing elements that establish charges related to incident light, charge storage elements that accumulate integrated charges transferred from the sensing elements, and diffusion nodes configured to establish measurement voltages representative of the integrated charges that are dumped from the charge storage elements. The pixel arrangement includes analog domain output circuitry comprising a measurement capacitance element that stores the measurement voltage, and a reset capacitance element that stores a reset voltage established at the diffusion node during a reset phase performed prior to a measurement phase. The analog domain output circuitry subtracts the stored reset voltage from the stored measurement voltage for processing into a pixel output voltage that at least partially reduces readout voltage uncertainty of the pixel arrangement.

Abstract: An active illumination range camera operable to determine distances to features in a scene, and comprising an illumination system and imaging system simultaneously controllable to provide a FOI and a FOV that coincide at, and are substantially coextensive with, a region of interest (ROI) in a portion of the scene and track the ROI as it moves.

Abstract: A CMOS time-of-flight image sensor must be robust to interface traps and fixed charges which may be present due to fabrication and which may cause an undesired induced electric field in the silicon substrate. This undesired induced electrical field is reduced by introducing a hydrogen-enriched dielectric material. Further remedial techniques can include applying ultraviolet light and/or performing a plasma treatment. Another possible approach adds a passivation doping layer at a top of the detector as a shield against the undesired induced electric field. One or more of the above techniques can be used to prevent any unstable behavior of the time-of-flight sensor.

Abstract: A camera includes a sensor array including a plurality of individually addressable sensor elements, each of the plurality of sensor elements responsive to incident light over a broad wavelength band. Covering the sensor array is a light valve switchable electronically between closed and open states. The light valve is configured to, in the closed state, block light of a stopband and transmit light outside the stopband, and, in the open state, transmit the light of the stopband. An electronic controller of the camera is configured to switch the light valve from the closed to the open state and, synchronously with switching the light valve, address the sensor elements of the sensor array.

Abstract: A sensor is provided, with the sensor including a reflective element and an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element and propagates in an optical cavity between the optical fiber and the reflective element. A first material is within the optical cavity and has a coefficient of thermal expansion and a thickness that compensate a refractive index change with temperature of a second material within the optical cavity.

Abstract: A CMOS time-of-flight image sensor must be robust to interface traps and fixed charges which may be present due to fabrication and which may cause an undesired induced electric field in the silicon substrate. This undesired induced electrical field is reduced by introducing a hydrogen-enriched dielectric material. Further remedial techniques can include applying ultraviolet light and/or performing a plasma treatment. Another possible approach adds a passivation doping layer at a top of the detector as a shield against the undesired induced electric field. One or more of the above techniques can be used to prevent any unstable behavior of the time-of-flight sensor.

Abstract: A time-of-flight detector includes a semiconductor layer and a light modulation structure. The semiconductor layer is configured to translate light radiation into electrical charge. The light modulation structure is configured to increase a path of interaction of light radiation through the semiconductor layer. In some example implementations, the light modulation structure is configured to deflect at least some light radiation at an increased angle through the semiconductor layer. In some example implementations, the light modulation structure is configured to reflect light radiation more than once through the semiconductor layer.

Abstract: A CMOS image sensor pixel has an integrated shallow trench isolation structure, resulting in higher optical sensitivity in general, and specifically for long wavelengths (red, near infrared, infrared). The shallow trench isolation structure acts as an optical grating that reflects and diffracts light so that an increased optical energy (photo generation) is observed in the photosensitive semiconductor layer of the pixel. An increase in dark current is avoided by passivating the shallow trench isolation structure with dopant which was implanted within the photosensitive semiconductor layer. Annealing in a standard CMOS process causes the dopant to diffuse toward the shallow trench isolation structure. The pixel can be configured as a time-of-flight sensor. The shallow trench isolation structure acts as a physical barrier for electrical charge motion, resulting in a higher modulation contrast pixel. Further, front side or backside illumination can be used.

Abstract: Optical apparatus and methods utilizing sensors operating in the reflection mode are provided. The apparatus includes at least one optical bus. The at least one optical bus is configured to be optically coupled to at least one source of input optical signals, to at least one optical detector, and to a plurality of reflective sensing elements. The at least one optical bus transmits an input optical signal from the at least one source to the plurality of reflective sensing elements. At least one reflective sensing element of the plurality of reflective sensing elements receives a portion of the input optical signal and reflects at least a portion of the received portion. The at least one optical bus transmits the reflected portion to the at least one optical detector.

Abstract: A sensor is provided, with the sensor including a reflective element and an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element and propagates in an optical cavity between the optical fiber and the reflective element. A first material is within the optical cavity and has a coefficient of thermal expansion and a thickness that compensate a refractive index change with temperature of a second material within the optical cavity.

Abstract: A method for fabricating a sensor is provided, with the sensor including a reflective element and an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element and propagates in an optical cavity between the optical fiber and the reflective element. The method includes positioning an element within the optical cavity. The element has a coefficient of thermal expansion and a thickness that compensate a refractive index change with temperature of a medium within the optical cavity.

Abstract: A method for fabricating a sensor is provided, with the sensor including a reflective element and an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element and propagates in an optical cavity between the optical fiber and the reflective element. The method includes positioning an element within the optical cavity. The element has a coefficient of thermal expansion and a thickness that compensate a refractive index change with temperature of a medium within the optical cavity.

Abstract: Optical apparatus and methods utilizing sensors operating in the reflection mode are provided. The apparatus includes at least one optical bus. The at least one optical bus is configured to be optically coupled to at least one source of input optical signals, to at least one optical detector, and to a plurality of reflective sensing elements. The at least one optical bus transmits an input optical signal from the at least one source to the plurality of reflective sensing elements. At least one reflective sensing element of the plurality of reflective sensing elements receives a portion of the input optical signal and reflects at least a portion of the received portion. The at least one optical bus transmits the reflected portion to the at least one optical detector.

Abstract: An optical structure includes an optical waveguide and at least one photonic crystal structure. The optical structure also includes a structural portion mechanically coupled to the optical waveguide and the at least one photonic crystal structure such that a region substantially bounded by the structural portion, the optical waveguide, and the at least one photonic crystal structure has a specified volume.

Abstract: An acoustic sensor includes a diaphragm having a reflective element. The sensor has an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element. A first end of the optical fiber and the reflective element form an optical cavity therebetween. The acoustic sensor further includes a structural element mechanically coupled to the diaphragm and the optical fiber. The structural element includes a material having a coefficient of thermal expansion substantially similar to the coefficient of thermal expansion of the optical fiber. For example, the material can be silica.

Abstract: An optical structure includes an optical waveguide and at least one photonic crystal structure. The optical structure also includes a structural portion mechanically coupled to the optical waveguide and the at least one photonic crystal structure such that a region substantially bounded by the structural portion, the optical waveguide, and the at least one photonic crystal structure has a specified volume.

Abstract: An optical structure on an optical fiber and a method of fabrication is provided. The optical structure includes an end of an optical fiber and a layer formed on the end of the optical fiber. The layer comprises one or more first portions having a first optical pathlength in a direction perpendicular to the layer and one or more second portions having a second optical pathlength in the direction perpendicular to the layer, the second optical pathlength different from the first optical pathlength.

Abstract: An acoustic sensor includes a diaphragm having a reflective element. The sensor has an optical fiber positioned relative to the reflective element such that light emitted from the optical fiber is reflected by the reflective element. A first end of the optical fiber and the reflective element form an optical cavity therebetween. The acoustic sensor further includes a structural element mechanically coupled to the diaphragm and the optical fiber. The structural element includes a material having a coefficient of thermal expansion substantially similar to the coefficient of thermal expansion of the optical fiber. For example, the material can be silica.

Abstract: An optical structure on an optical fiber and a method of fabrication is provided. The optical structure includes an end of an optical fiber and a layer formed on the end of the optical fiber. The layer comprises one or more first portions having a first optical pathlength in a direction perpendicular to the layer and one or more second portions having a second optical pathlength in the direction perpendicular to the layer, the second optical pathlength different from the first optical pathlength.

Abstract: An acoustic sensor and a method of fabricating an acoustic sensor are provided. The acoustic sensor includes at least one photonic crystal structure and an optical fiber having an end optically coupled to the at least one photonic crystal structure. The acoustic sensor further includes a structural portion mechanically coupled to the at least one photonic crystal structure and to the optical fiber. The at least one photonic crystal structure, the optical fiber, and the structural portion substantially bound a region having a volume such that a frequency response of the acoustic sensor is generally flat in a range of acoustic frequencies.