Abstract: A system for optical cooling comprises a substrate and a first waveguide supported by the substrate, with the first waveguide configured to provide optical cooling by fluorescence up-conversion. A first optical fiber is coupled to the first waveguide, with the first optical fiber configured to deliver cooling light to the first waveguide. A second waveguide is supported by the substrate, with the second waveguide adjacent to or coincident with the first waveguide. The interaction of the cooling light with the first waveguide produces a zone of local optical refrigeration based on the fluorescence up-conversion, such that the second waveguide is optically cooled by physical proximity to the first waveguide.

Abstract: An atomic clock is provided. An output of a tunable LO is coupled to a user output of the atomic clock. A charge pump adjusts the tunable LO with a LO tuning voltage. A follower circuit sets an output frequency of the atomic clock to a frequency of an external reference signal coupled to an external reference input. An atom referenced circuit sets the output frequency of the atomic clock to a frequency based on stored operating settings. A controller stores then current operating settings generated based on a then current external reference signal coupled to the external reference input. The controller is further configured to apply the stored then current operating settings to the atom referenced circuit when the then current external reference signal is removed from the external reference input to maintain the output frequency of the atomic clock at the output frequency set by the follower circuit.

Abstract: A turning grating coupler device comprises a waveguide core layer including a grating structure and an output slab adjoined with the grating structure. The grating structure comprises an array of sub-waveguides substantially parallel to each other along a first propagation direction. Each of the sub-waveguides has opposing sidewalls, and a width of each sub-waveguide is defined by a distance between the sidewalls. The width of each sub-waveguide is varied such that each of the sidewalls has a periodic structure that produces a sidewall periodic modulation that is out of phase with respective sidewall periodic modulations of adjacent neighboring sub-waveguides. An input edge is configured to receive a light beam from a source and direct the beam into the array of sub-waveguides in the first propagation direction. The sub-waveguides are configured to diffract the beam into the output slab in a second propagation direction substantially perpendicular to the first propagation direction.

Abstract: An atomic clock is provided. An output of a tunable LO is coupled to a user output of the atomic clock. A charge pump adjusts the tunable LO with a LO tuning voltage. A follower circuit sets an output frequency of the atomic clock to a frequency of an external reference signal coupled to an external reference input. An atom referenced circuit sets the output frequency of the atomic clock to a frequency based on stored operating settings. A controller stores then current operating settings generated based on a then current external reference signal coupled to the external reference input. The controller is further configured to apply the stored then current operating settings to the atom referenced circuit when the then current external reference signal is removed from the external reference input to maintain the output frequency of the atomic clock at the output frequency set by the follower circuit.

Abstract: In some embodiments, a system includes a laser that generates an optical signal and a resonator that receives the optical signal. The resonator includes an optical resonator cavity comprising a first and second end, wherein the optical signal propagates at a resonant frequency; a first optical anti-resonator terminating the first end and having a first stopband; and a second optical anti-resonator terminating the second end and having a second stopband. The system includes a detector that generates an electrical signal from a modified resonator output of the resonator; and Pound-Drever-Hall servo circuitry configured to generate control signals for controlling a frequency of the optical signal generated by the laser or phase modulation devices attached to the optical resonator cavity or the first or second optical anti-resonator, wherein each phase modulation changes a length of at least one of the optical resonator cavity or the first or second optical anti-resonator.

Abstract: Embodiments relating to an integrated photonics air data system are disclosed. A light beam from a laser source is routed to a plurality of tunable optical filters operative to transmit the light beam to one of a plurality of emitting grating couplers at any given time. The tunable optical filters are configured such that the light beam is emitted into the region of interest at different times from each of the emitting grating couplers. A passive optical filter array is configured to receive scattered light from the emitted light beam. The passive optical filter array comprises a plurality of optical notch filters operative for frequency selection, and a plurality of optical detectors each respectively coupled to an output of one of the optical notch filters. The passive optical filter array is operative to perform frequency spectrum decomposition of the received scattered light into a plurality of signals.

Abstract: A thermal metamaterial device comprises at least one MEMS thermal switch, including a substrate layer including a first material having a first thermal conductivity, and a thermal bus over a first portion of the substrate layer. The thermal bus includes a second material having a second thermal conductivity higher than the first thermal conductivity. An insulator layer is over a second portion of the substrate layer and includes a third material that is different from the first and second materials. A thermal pad is supported by a first portion of the insulator layer, the thermal pad including the second material and having an overhang portion located over a portion of the thermal bus. When a voltage is applied to the thermal pad, an electrostatic interaction occurs to cause a deflection of the overhang portion toward the thermal bus, thereby providing thermal conductivity between the thermal pad and the thermal bus.

Abstract: An optical device comprises a substrate layer having an upper surface, and a waveguide layer over the upper surface of the substrate layer. The waveguide layer comprises an input waveguide defined by a first waveguide portion having a first refractive index; an input slab defined by the first waveguide portion, the input slab adjoined with the input waveguide; and a microlens array defined by a second waveguide portion having a second refractive index that is different from the first refractive index. The microlens array is in optical communication with the input waveguide through the input slab. The microlens array is configured to receive a diverging planar light beam from the input slab along a direction of propagation. The microlens array is configured to control a far-field emission of the light beam such that an emission profile of the light beam exhibits a substantially uniform intensity.

Abstract: A nonlinear wave mixing system with grating assisted phase matching is provided. The system includes a pump laser and a nonlinear waveguide. The pump laser is used to generate pump light at a select wavelength. The nonlinear waveguide is configured to generate produced light from the pump light that is directed into the nonlinear waveguide. The nonlinear waveguide includes at least one backward grating that is configured to diffract the produced light in a backward direction relative to a direction the produced light travels in the nonlinear waveguide to reach the backward grating. The backward grating having a grating momentum that generates counter-propagating phase matching in the produced light.

Abstract: A system includes a quantum light device comprising a light source configured to emit a plurality of pairs of photons, wherein each pair of photons of the plurality of pairs of photons occupies a quantum entangled state. The system also includes optical circuitry configured to receive a first set of photons and a second set of photons. A set of photon detectors may receive the first set of photons and the second set of photons from the optical circuitry. Additionally, the system may include processing circuitry configured to determine, based on a set of time signals corresponding to each photon detector of the set of photon detectors, whether a time delay value exists in which a Clauser, Home, Shimony and Holt (CHSH) parameter is greater than a threshold CHSH parameter value.

Abstract: Embodiments relating to an integrated photonics air data system are disclosed. A light beam from a laser source is routed to a plurality of tunable optical filters operative to transmit the light beam to one of a plurality of emitting grating couplers at any given time. The tunable optical filters are configured such that the light beam is emitted into the region of interest at different times from each of the emitting grating couplers. A passive optical filter array is configured to receive scattered light from the emitted light beam. The passive optical filter array comprises a plurality of optical notch filters operative for frequency selection, and a plurality of optical detectors each respectively coupled to an output of one of the optical notch filters. The passive optical filter array is operative to perform frequency spectrum decomposition of the received scattered light into a plurality of signals.

Abstract: A nonlinear wave mixing system with grating assisted phase matching is provided. The system includes a pump laser and a nonlinear waveguide. The pump laser is used to generate pump light at a select wavelength. The nonlinear waveguide is configured to generate produced light from the pump light that is directed into the nonlinear waveguide. The nonlinear waveguide includes at least one backward grating that is configured to diffract the produced light in a backward direction relative to a direction the produced light travels in the nonlinear waveguide to reach the backward grating. The backward grating having a grating momentum that generates counter-propagating phase matching in the produced light.

Abstract: A nonlinear wave mixing system with grating assisted phase matching is provided. The system includes a pump laser and a nonlinear waveguide. The pump laser is used to generate pump light at a select wavelength. The nonlinear waveguide is configured to generate produced light from the pump light that is directed into the nonlinear waveguide. The nonlinear waveguide includes at least one backward grating that is configured to diffract the produced light in a backward direction relative to a direction the produced light travels in the nonlinear waveguide to reach the backward grating. The backward grating having a grating momentum that generates counter-propagating phase matching in the produced light.

Abstract: An optical device comprises a waveguide core layer that includes a planar lens structure having a first end and a second end, with the planar lens structure including a plurality of lens tapers extending from at least one of the first or seconds ends in a convex-shaped array. The waveguide core layer also includes a waveguide slab that adjoins with the planar lens structure, such that the waveguide slab is in optical communication with the plurality of lens tapers. The plurality of lens tapers are configured to adiabatically transition an index of refraction from a first index value, external to the planar lens structure, to a second index value, internal to the planar lens structure.

Abstract: Techniques relating to an improved optical waveguide are described. The optical waveguide includes an upper and lower waveguide that each comprise a first and second layer, in which photons are transferred from the lower waveguide to the upper waveguide. A structured subwavelength coupling region is included, for example, in the first upper waveguide layer. The fill factor of the subwavelength grating coupling region is increased in the direction of light propagation to increase the index of refraction of the structured subwavelength coupling region and therefore improve photon transfer from the lower waveguide. Additionally, the width of the optical waveguide (at least along the structured subwavelength coupling region) remains constant as the fill factor increases.

Abstract: Systems and embodiments for a multi-pixel waveguide optical receiver are described herein. In certain embodiments, a system includes an emitter that emits laser light towards a surface. The system also includes a receiver that passively receives reflected laser light that is a portion of the laser light reflected from the surface, wherein the receiver has multiple pixels having a size that is smaller than an expected optical speckle size, wherein the expected optical speckle size corresponds to a region on the receiver where the reflected laser light has a substantially uniform spatial phase. Additionally, the system includes a combiner configured to combine optical fields from each pixel in the multiple pixels into an output that supports a number of modes that is equal to a number of pixels in the multiple pixels. Moreover, the system includes a photodetector configured to receive light from the output.

Abstract: An optical device comprises a waveguide core layer that includes a planar lens structure having a first end and a second end, with the planar lens structure including a plurality of lens tapers extending from at least one of the first or seconds ends in a convex-shaped array. The waveguide core layer also includes a waveguide slab that adjoins with the planar lens structure, such that the waveguide slab is in optical communication with the plurality of lens tapers. The plurality of lens tapers are configured to adiabatically transition an index of refraction from a first index value, external to the planar lens structure, to a second index value, internal to the planar lens structure.

Abstract: Among other embodiments, a method for generated entangled photons is disclosed. The method comprises generating photons in a fundamental mode and converting the photons from the fundamental mode to a higher-order mode. The method further comprises generating, by a Bragg resonator configured to receive the photons, entangled photons in the fundamental mode from the converted photons in the higher-order mode. The method further comprises outputting the generated entangled photons from the Bragg resonator.

Abstract: Improved architectures and related methods for enhancing entangled photon generation in optical systems are described. Photons from a light source are coupled from the fundamental mode into an optical resonator in a higher-order mode. The optical resonator comprises a photon generation portion configured to generate entangled photons from the coupled photons. The entangled photons are selectively extracted from the optical resonator in the fundamental mode while the remaining photons propagate through the optical resonator mode and combine with the source photons entering the optical resonator. While the source photons propagating or entering the optical resonator resonate within the optical resonator, the entangled photons are not resonant with the optical resonator, and are selectively extracted before traversing a complete cycle in the optical resonator. Extracted entangled photons can then be output for use in, for example, a communication system.

Abstract: Systems and methods for a silicon photonics integrated optical velocimeter are provided herein. In some embodiments, a method includes producing a laser output at a laser source; emitting the laser output from a plurality of emitters formed in an optical chip; receiving a plurality of reflected portions of the emitted laser output at an optical collector formed in the optical chip, wherein the plurality of reflected portions are reflected off of at least one surface; beating the laser output against the reflected portions of the emitted laser output, wherein one of the laser output or the reflected portions of the emitted laser output are modulated by at least one modulation frequency; and calculating a doppler shift for each of the plurality of reflected portions of the emitted laser output based on an output of the beating and the at least one modulation frequency.