Photonic chip includes an external cavity (EC) optical circuit to provide wavelength-selective optical feedback to a length of active optical fiber. Light generated in the active optical fiber may be coupled from the EC circuit to a light processing circuit of the photonic chip, such as an optical modulator or an optical mixer. The EC circuits may include single-frequency and multi-frequency optical filters, which may include ring resonators, dual-ring resonators, and optical modulators to support multi-frequency lasers. The EC circuits may further include pump combiners and optical isolators.

In the examples provided herein, a system includes an input waveguide, where a first end of the input waveguide is coupled to a light-emitting optical transmitter to allow the emitted light to enter the input waveguide, and a first ring resonator tunable to be resonant at a first resonant wavelength, wherein the first ring resonator is positioned near the input waveguide to couple a light at the first resonant wavelength from the input waveguide to the first ring resonator. The system also has a bus waveguide positioned to couple the light at the first resonant wavelength in the first ring resonator to the bus waveguide, and a mechanism to wavelength-tune the first ring resonator to a particular wavelength.

A high Q whispering gallery mode resonator with ion-implanted voids is described. A resonator device includes a resonator disk formed of an electrooptic material. The resonator disk includes a top surface, a bottom surface substantially parallel to the top surface, and a side structure between the top surface and the bottom surface. The side structure includes an axial surface along a perimeter of the resonator disk, where a midplane passes through the axial surface dividing the axial surface into symmetrical halves. The whispering gallery mode resonator disk includes voids localized at a particular depth from the top surface. At least one of the voids localized at the particular depth from the top surface is located at an outer extremity towards the perimeter of the resonator disk. The resonator device can further include a first electrode on the top surface and a second electrode on the bottom surface.

A method for fabricating a thick crack-free dielectric film on a wafer for device fabrication is disclosed herein. A stress-release pattern is fabricated in an oxide layer of the wafer, which surrounds a number of device regions. The stress-release pattern comprises a plurality of recessions, which are spaced periodically along at least one direction. The plurality of recessions interrupt the continuous film during the dielectric film deposition, to prevent cracks from forming in the dielectric film and propagating into the device regions. Such that, a thick crack-free dielectric film can be achieved in the device regions, which are formed by patterning the dielectric layer. Furthermore, conditions of the dielectric film deposition process can be tuned to ensure quality of the deposited dielectric film. Still further, a plurality of deposition runs may be performed to deposit the thick crack-free dielectric film.

Techniques for the integration of SiGe/Si optical resonators with qubit and CMOS devices using structured substrates are provided. In one aspect, a waveguide structure includes: a wafer; and a waveguide disposed on the wafer, the waveguide having a SiGe core surrounded by Si, wherein the wafer has a lower refractive index than the Si (e.g., sapphire, diamond, SiC, and/or GaN). A computing device and a method for quantum computing are also provided.

Based on graphene heterostructure in chip-scale silicon nitride microresonators, optoelectronic control and modulation in frequency combs via group velocity dispersion modulation can be demonstrated. By tuning graphene Fermi level from 0.50 eV to 0.65 eV via electric-field gating, deterministic in-cavity group velocity dispersion control from anomalous (62 fs.sup.2/mm) to normal (+9 fs.sup.2/mm) can be achieved with Q factor remaining high at 10.sup.6. Consequently, both the primary comb lines and the full comb spectra can be controllable dynamically with the on/off switching of the Cherenkov radiation, the tuning of the primary comb lines from 2.3 THz to 7.2 THz, and the comb span control from zero comb lines to 781 phase-locked comb lines, directly via the DC voltage.

The present invention concerns an optical coupling device including at least one supporting layer comprising a first support wall and a second support wall. The at least one supporting layer comprises at least one bridging waveguide for coupling electromagnetic radiation to and from an optical resonator or optical device, the at least one bridging waveguide extending between the first support wall and the second support wall.

A device system for constituting a 3D image sensor based on optical phased array is provided. The device system includes an optical modulator that is integrated on the same photonic integrated circuit (PIC) chip as a laser diode array with different output wavelengths and a multiplexer for transmitting an optical wave having a wavelength selected from the laser diode array to an optical waveguide and modulates the optical wave into a specific optical signal, an optical phased array that radiates the optical signal received via an optical switch to the free space using a tunable transmit and receive (TRx) antenna array, and a photodetector that converts an Rx optical signal received by a Tx optical signal transmitted via the optical phased array into an electrical signal.

Techniques for the integration of SiGe/Si optical resonators with qubit and CMOS devices using structured substrates are provided. In one aspect, a waveguide structure includes: a wafer; and a waveguide disposed on the wafer, the waveguide having a SiGe core surrounded by Si, wherein the wafer has a lower refractive index than the Si (e.g., sapphire, diamond, SiC, and/or GaN). A computing device and a method for quantum computing are also provided.

An optical cavity includes a ring defining an internal boundary and an external boundary, at least one of which is periodically modulated to define a gear-shaped configuration including a plurality of teeth, thereby enabling a plurality of slow-light modes. At least one physical defect may be defined within the periodically modulated internal boundary and/or external boundary to thereby enable at least one localized mode. At least one waveguide is coupled to the ring.