Abstract: An optical receiver, used in wavelength-division multiplexing, has multiple photodetectors per channel. The optical receiver comprises a demultiplexer to separate incoming light into different output waveguides, one output waveguide for each channel. A splitter is used in each output waveguide to split each output waveguide into two or more branches. A separate photodetector is coupled with each branch so that two or more photodetectors are used to measure each channel.

Abstract: A photonic integrated circuit (PIC) is described. This PIC includes a semiconductor-barrier layer-semiconductor diode in an optical waveguide that conveys an optical signal, where the barrier layer is an oxide or a high-k material. Moreover, semiconductor layers in the semiconductor-barrier layer-semiconductor diode may include geometric features (such as a periodic pattern of holes or trenches) that create a lattice-shifted photonic crystal optical waveguide having a group velocity of light that is lower than the group velocity of light in the first semiconductor layer and the second semiconductor layer without the geometric features. The optical waveguide is included in an optical modulator, such as a Mach-Zehnder interferometer (MZI).

Abstract: An optical, directional coupler has a first input, a second input, a first output, and a second output. The coupler is made with a shoulder disposed on a substrate and a first ridge and a second ridge disposed on the shoulder. The first ridge extends from the first input to the first output. The second ridge extends from the second input to the second output. The shoulder, the first ridge, and the second ridge taper to provide coupling and are modified to select a coupling ratio.

Abstract: A photonic integrated circuit (PIC) is described. This PIC includes a grating coupler for surface-normal coupling that has an alternating pattern of grating teeth and grating trenches, where the grating trenches are filled with an electro-optical material. By applying an electric potential to the grating teeth, the index of refraction of the electro-optical material can be modified.

Abstract: Embodiments of the present disclosure provide a device control method and a device. The method includes the following steps: receiving, by a terminal, a radio signal sent by a first access point device (S101), determining a corresponding first signal strength according to the radio signal sent by the first access point device (S102), acquiring a second signal strength, corresponding to the first access point device, of a first controlled device and a third signal strength, corresponding to the first access point device, of a second controlled device (S103), and when determining, according to the first signal strength, the second signal strength, and the third signal strength, that a distance between the first controlled device and the terminal is less than a distance between the second controlled device and the terminal, controlling the first controlled device and the second controlled device (S104).

Abstract: A high-order-mode (HOM) filter for thick silicon waveguides has a shoulder slab, a waveguide ridge, a first filter ridge, and a second filter ridge. The first filter ridge and the second filter ridge help attenuate higher-order modes from the waveguide ridge while the waveguide ridge guides a fundamental mode.

Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.

Abstract: A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.

Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.

Abstract: An integrated optical device includes an electro-absorption modulator disposed on a top surface of an optical waveguide. The electro-absorption modulator includes germanium disposed in a cavity between an n-type doped silicon sidewall and a p-type doped silicon sidewall. By applying a voltage between the n-type doped silicon sidewall and the p-type doped silicon sidewall, an electric field can be generated in a plane of the optical waveguide, but perpendicular to a propagation direction of the optical signal. This electric field shifts a band gap of the germanium, thereby modulating the optical signal.

Abstract: An optical source is described. This optical source includes a semiconductor optical amplifier, with a semiconductor other than silicon, which provides a gain medium. In addition, a photonic chip, optically coupled to the semiconductor optical amplifier, includes: an optical waveguide that conveys the optical signal; and a pair of ring-resonator modulators that modulate the optical signal. Furthermore, the pair of ring-resonator modulators is included within an optical cavity in the optical source. For example, the optical cavity may be defined by a reflective coating on one edge of the semiconductor optical amplifier and a reflector on one end of the optical waveguide. Alternatively, the optical cavity may be defined by reflectors on ends of the optical waveguide.

Abstract: A method of fabricating a waveguide mode expander includes providing a substrate including a waveguide, bonding a chiplet including multiple optical material layers in a mounting region adjacent an output end of the waveguide, and selectively removing portions of the chiplet to form tapered stages that successively increase in number and lateral size from a proximal end to a distal end of the chiplet. The first optical material layer supports an input mode substantially the same size as a mode exiting the waveguide. One or more of the overlying layers, when combined with the first layer, support a larger, output optical mode size. Each tapered stage of the mode expander is formed of a portion of a respective layer of the chiplet. The first layer and the tapered stages form a waveguide mode expander that expands an optical mode of light traversing the chiplet.

Abstract: A technique for fabricating a hybrid optical source is described. During this fabrication technique, a III-V compound-semiconductor active gain medium is integrated with a silicon-on-insulator (SOI) chip (or wafer) using edge coupling to form a co-planar hybrid optical source. Using a backside etch-assisted cleaving technique, and a temporary transparent substrate with alignment markers, a III-V compound-semiconductor chip with proper edge polish and coating can be integrated with a processed SOI chip (or wafer) with accurate alignment. This fabrication technique may significantly reduce the alignment complexity when fabricating the hybrid optical source, and may enable wafer-scale integration.

Abstract: An optical-source monitor images and diffracts received optical signals using an optical device that has a reflective geometry. For example, the optical device may include a diffraction grating on a curved surface, such as an echelle grating. By imaging and diffracting the optical signals, the optical device may couple to the optical signals on different diffraction orders of the optical device (which have different carrier wavelengths) from input optical waveguides to corresponding output optical waveguides. Then, output power monitors may measure the output power levels of the optical signals, and control logic may provide wavelength control signals to optical sources that provide the optical signals based on measured output power levels.

Abstract: An optical device is described. This optical device includes multiple components, such as a ring resonator, an optical waveguide and a grating coupler, having a common etch depth (which is associated with a single etch step or operation during fabrication). Moreover, these components may be implemented in a semiconductor layer in a silicon-on-insulator technology. By using a common etch depth, the optical device may provide: compact active devices, multimode ultralow-loss optical waveguides, high-speed ring resonator modulators with ultralow power consumption, and compact low-loss interlayer couplers for multilayer-routed optical links. Furthermore, the single etch step may help reduce or eliminate optical transition loss, and thus may facilitate high yield and low manufacturing costs.

Abstract: An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.

Abstract: In an optical device, a ring resonator, having a resonance wavelength, optically couples an optical signal that includes a wavelength from an input optical waveguide to an output optical waveguide. A monitoring mechanism in the optical device, which is optically coupled to the output optical waveguide, monitors an output optical signal on the output optical waveguide. For example, the monitoring mechanism may dither a temperature of the ring resonator at a frequency using a heater, and the output optical signal may be monitored by determining amplitude and phase information of the output optical signal at the frequency and twice the frequency. Moreover, control logic in the optical device adjusts the resonance wavelength based on the monitored output optical signal, where the adjustment is made without monitoring an input optical signal on the input optical waveguide.

Abstract: Using silicon photonic components that support a single polarization, the output of an optical receiver is independent of the polarization of an optical signal. In particular, using a polarization-diversity technique, the two orthogonal polarizations in a single-mode optical fiber are split in two and processed independently. For example, the two optical signals are provided by a polarizing splitting grating coupler. Subsequently, a wavelength channel in the two optical signals is selected using a wavelength-selective filter (for example, using a ring resonator or an echelle grating) and combined at an optical detector (such as a photo-detector) to achieve polarization-independent operation.

Abstract: A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.

Abstract: A chip package includes an optical integrated circuit (such as a hybrid integrated circuit) and an integrated circuit that are adjacent to each in the chip package. The integrated circuit includes electrical circuits, such as memory or a processor, and the optical integrated circuit communicates optical signals with very high bandwidth. Moreover, a front surface of the integrated circuit is electrically coupled to a front surface of the optical integrated circuit by a top surface of the interposer, where the top surface faces the front surface of the integrated circuit and the front surface of the optical integrated circuit. Furthermore, the integrated circuit and the optical integrated circuit may be on a same side of the interposer. By integrating the optical integrated circuit and the integrated circuit in close proximity, the chip package may facilitate improved performance compared to chip packages with electrical interconnects.