Aspects of the present disclosure describe planar lightwave circuit systems, methods and structures including a resonant mirror assembly having cascaded resonators that provide or otherwise facilitate the control of the transmissivity/reflectivity of a planar lightwave circuit (PLC)—or portion thereof—over a range of 0% to substantially 100%.

A photonic node includes a first circuit disposed on a first substrate and a second circuit disposed on a second substrate different from the first substrate. The first circuit is configured to route light signals originated from the photonic node to local nodes of a local group in which the photonic node is a member. The second circuit is configured to route light signals received from a node of an external group in which the photonic node is not a member, to one of the local nodes.

A first portion of incoming light and a second portion of incoming light travel in opposite directions within a first optical waveguide. A ring resonator in-couples the first portion of incoming light and the second portion of incoming light from the first optical waveguide, such that the first portion of incoming light and the second portion of incoming light travel in opposite directions within the ring resonator. A second optical waveguide is disposed to in-couple the first portion of incoming light and the second portion of incoming light couple from the ring resonator, such that the first portion of incoming light and the second portion of incoming light travel in opposite directions within the second optical waveguide away from the ring resonator. One or more photodetector(s) are optically connected to receive the first portion of incoming light and the second portion of incoming light from the second optical waveguide.

Integrated optical filter and photodetectors and methods of fabrication thereof are described herein according to the present disclosure. An example of an integrated optical filter and photodetector described herein includes a substrate, an insulator layer on the substrate, and a semiconductor layer on the insulator layer. An optical filter having a resonant cavity is formed in or on the semiconductor layer. The integrated optical filter and photodetector further includes two first metal fingers and a second metal finger interdigitated between the two first metal fingers on the semiconductor layer forming Schottky barriers. The first metal fingers are constructed from a different metal relative to the second metal finger.

An photonic circuit includes a substrate, a plurality of first light waveguides disposed on the substrate, the first light waveguides extending in a first direction, a plurality of second light waveguides disposed on the substrate and extending in a second direction intersecting the first direction, and a plurality of first micro-ring resonators disposed on the substrate. Each of the first light waveguides has an intersection with each of the second light waveguides. Each of the intersections is provided with a first micro-ring resonator of the first micro-ring resonators. Each first micro-ring resonator is configured to route signals of a respective wavelength from one of the light waveguides at the intersection to another light waveguide at the intersection.

An Optical Dispersion Compensator (ODC) is disclosed, the ODC being suitable for managing chromatic dispersion of an optical signal for transmission over an optical fiber. The ODC comprises a first ODC unit (202) arranged on a first optical bus (206), a second ODC unit (204) arranged on a second optical bus (208), parallel to the first optical bus (206), and a switching element (210) interconnecting the first and second optical buses (206, 208) between the first and second ODC units (202, 204). The first and second ODC units (202, 204) are operable to provide a delay to the optical signal that varies with frequency. The switching element (210) is configured, in a first state, to switch an optical signal received on one of the first or second optical buses (206, 208) to the other of the first or second optical buses (208, 206) and, in a second state, to maintain an optical signal received on one of the first or second optical buses (206, 208) on the optical bus on which it was received (206, 208). Reflective elements (710) may be included in the ODC, providing bidirectional propagation through one of more ODC units.

Technologies for quantum sensing are disclosed. In the illustrative embodiment, a sensor system may be operated by coupling an electromagnetic wave from a measurement line to a first resonator. The sensor system includes a second resonator that is non-reciprocally coupled to the first resonator. In the absence or a perturbation, there is no reciprocal coupling between the first resonator and the second resonator, but a perturbation may cause reciprocal coupling between the first and second resonator. With appropriate selection of the non-reciprocal coupling, the signal at the output of the measurement line may allow for fast determination of whether the perturbation is present.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

A ring resonator electro-optical device includes a first silicon nitride waveguide and a second annular silicon waveguide that comprises a first section running under a second section of the first waveguide. The second waveguide also includes an annular silicon strip having a cross-section increasing in the first section from a minimum cross-section located under the second section.

Disclosed herein is an integrated photonics device including a frequency stabilization subsystem for monitoring and/or adjusting the wavelength of light emitted by one or more light sources. The device can include one or more selectors that can combine, select, and/or filter light along one or more light paths, which can include light emitted by a plurality of light sources. Example selectors may include, but are not limited to, an arrayed waveguide grating (AWG), a ring resonator, a plurality of distributed Bragg reflectors (DBRs), a plurality of filters, and the like. Output light paths from the selector(s) can be input into one or more detector(s). The detector(s) can receive the light along the light paths and can generate one or more signals as output signal(s) from the frequency stabilization subsystem. A controller can monitor the wavelength and can adjust or generate control signal(s) for the one or more light sources to lock the monitored wavelength to a target wavelength (or within a targeted range of wavelengths).