An optical communication component includes three or more couplers, a pair of waveguides, a phase shifter, a detector, and a controller. Each of the couplers multiplexes two input optical signals and two-branch outputs the multiplexed optical signals. Each of the pair of waveguides connects between the couplers and outputs each of the optical signals two-branch output from one of the couplers to another one of the couplers. The phase shifter, included in each of the waveguides, adjusts a phase amount of each of the optical signals passing through the waveguides. The detector detects an amount of power of the optical signal that has been subjected to phase adjustment and that is two-branch output from a most downstream coupler, from among the couplers, located in the traveling direction of the optical signal. The controller controls, based on the detected amount of power, each of the phase shifters.

To reduce the size while being able to accurately monitor light of a plurality of wavelengths. An optical multiplexing circuit includes: a plurality of branching units each configured to divide light output from a corresponding one of a plurality of input waveguides; a multiplexing unit configured to multiplex beams each being one beam of the light divided by each of the plurality of branching units; an output waveguide configured to output the light multiplexed by the multiplexing unit; and a plurality of monitoring waveguides each configured to output another beam of the light divided by each of the plurality of branching units, wherein at least one monitoring waveguide of the plurality of monitoring waveguides includes a bent waveguide constituted by a rib-shaped waveguide.

A circuit for detecting an optical data signal includes a photonics substrate and first and second photodiodes formed in the photonics substrate. The first photodiode is configured to receive, via an input port formed in the photonics substrate, a first portion of the optical data signal and convert light power of the first portion of the optical data signal to generate a first current based on the optical data signal. The second photodiode is configured to output a second current without receiving any portion of the optical data signal. The second current corresponds to a dark current induced in the second photodiode. The circuit is configured to subtract the second current from the first current to generate an output signal corresponding to a power of the optical data signal without dark current induced in the first photodiode.

Various embodiments of the present disclosure are directed towards an integrated chip including a protective ring structure overlying a grating coupler structure. A waveguide structure is disposed within a semiconductor substrate and comprises the grating coupler structure. An interconnect structure overlies the semiconductor substrate. The interconnect structure includes a contact etch stop layer (CESL) and a conductive contact over the semiconductor substrate. The conductive contact extends through the CESL. The protective ring structure extends through the CESL and has an upper surface aligned with an upper surface of the conductive contact.

A photonics sensing system includes, in part, first and second multipath integrated optical networks, an optical radiator, and an optical receiver. The first multipath integrated optical network includes, in part, N optical delay elements each supplying one of N delayed optical signals of a received optical pulse, N optical modules each supplying a portion of a different one of the N delayed optical signals, and an optical combiner adapted to combine the N delayed portions to generate a modulated optical signal. The smallest of the N delays is smaller than a width of the received optical pulse. The optical radiator is adapted to radiate the modulated optical signal. The optical receiver is adapted to receive a reflection of the transmitted signal. The second multipath integrated optical network is adapted to demodulate the reflected signal received by the optical receiver.

A multi-level semiconductor device, the device including: a first level including integrated circuits; a second level including a structure designed to conduct electromagnetic waves, where the second level is disposed above the first level, where the first level includes crystalline silicon; an oxide layer disposed between the first level and the second level; and a plurality of electromagnetic modulators, where the second level is bonded to the oxide layer, and where the bonded includes oxide to oxide bonds.

An optical-communication module includes an arrayed waveguide grating; a light transmitter including light-emitting elements for emitting first signal beams into the arrayed waveguide grating, wherein the first signal beams are converged into one first communication beam in the arrayed waveguide grating; a wavelength division multiplexing filter is used to transmit the first communication beam emitted by the arrayed waveguide grating to an optical fiber; an optical receiver including optical sensor for sensing second signal beams emitted from the arrayed waveguide grating. The optical fiber is used for transmitting a second communication beam to the wavelength division multiplexing filter. The second communication light beam enters the arrayed waveguide grating through the wavelength division multiplexing filter. The second communication beam is divided into the second signal beams in the arrayed waveguide grating.

The disclosed technology can be implemented in photonics integrated circuit (PIC) to provide an optical frequency detection device for measuring an optical frequency of light using two Mach-Zehnder interferometer where the delay imbalance in the first interferometer is configured to be one quarter wavelength longer than that of the second interferometer to produce an additional phase difference between the two arms. The two outputs of each interferometer are then detected by two photodetectors to produce two complementary interference signals. The difference between the two complementary interference signals of the first interferometer is a sine function of the optical frequency while the difference between the two complementary interference signals of the second interferometer is proportional to a cosine function of the optical frequency. Using the sine/cosine interpretation algorithm commonly used for the rotation encoders/decoders, any increments in optical frequency can be readily obtained.

Examples described herein relate to an optical device, such as, a ring resonator, that includes a ring waveguide. The ring resonator includes a ring waveguide to allow passage of light therethrough. Further, the ring resonator includes a modulator formed along a first section of the circumference of the ring waveguide to modulate the light inside the ring waveguide based on an application of a first reverse bias voltage to the modulator. Moreover, the ring resonator includes an avalanche photodiode (APD) isolated from the modulator and formed along a second section of the circumference of the ring waveguide to detect the intensity of the light inside the ring waveguide based on an application of a second reverse bias voltage to the APD. The second section is shorter than the first section, and the second reverse bias voltage is higher than the first reverse bias voltage.

An optical device includes: a substrate; an optical waveguide that forms a Mach-Zehnder interferometer; a signal electrode; and a ground electrode. The optical waveguide is placed between the signal electrode and the ground electrode. An electric field is generated in a direction along a surface of the substrate when a voltage is applied between the signal electrode and the ground electrode. The optical waveguide includes a first waveguide through which input light propagates, a curved waveguide which is optically coupled to the first waveguide, and a second waveguide which is optically coupled to the curved waveguide. The signal electrode includes first and second electrodes that are respectively placed near the first and second waveguides. An electric signal is supplied to the first electrode, and an inverted electric signal is supplied to the second electrode.