Abstract: Absolute temperature measurements of integrated photonic devices can be accomplished with integrated bandgap temperature sensors located adjacent the photonic devices. In various embodiments, the temperature of the active region within a diode structure of a photonic device is measured with an integrated bandgap temperature sensor that includes one or more diode junctions either in the semiconductor device layer beneath the active region or laterally adjacent to the photonic device, or in a diode structure formed above the semiconductor device layer and adjacent the diode structure of the photonic device.

Abstract: Described are various configurations of high-speed via structures. Various embodiments can reduce or entirely eliminate insertion loss in high-speed signal processing environments by using impedance compensation structures that decrease a mismatch in components of a circuit. An impedance compensation structure can include a metallic structure placed near a via to lower an impedance difference between the via and a conductive pathway connected to the via.

Abstract: Photonic ring modulators with high tuning efficiency and small footprint can be formed in a hybrid material platform from a silicon bus waveguide vertically coupled to an optically active compound semiconductor (e.g., III-V) ring resonator. The performance of the modulator, e.g., in terms of the tuning efficiency and the maximum insertion loss, may be optimized by suitable levels of an applied bias voltage and a heater power of a heater optionally included in the ring modulator. The disclosed hybrid photonic ring modulators may be used, e.g., in photonic transceiver circuits with high lane count.

Abstract: Methods and systems are presented for heterogeneous integration of photonics and electronics with atomic layer deposition (ALD) bonding. One method includes operations for forming a compound semiconductor and for depositing (e.g., via atomic layer deposition) a continuous film of a protection material (e.g., Al2O3) on a first surface of the compound semiconductor. Further, the method includes an operation for forming a silicon on insulator (SOI) wafer, with the SOI wafer comprising one or more waveguides. The method further includes bonding the compound semiconductor at the first surface to the SOI wafer to form a bonded structure and processing the bonded structure. The protection material protects the compound semiconductor from acid etchants during further processing of the bonded structure.

Abstract: An example photonic integrated circuit includes a transmitter circuit with a optical communication path to an optical coupler configured to couple with an optical fiber. The optical communication path has a propagation direction away from the transmitter circuit and towards the optical coupler. A counter-propagating tap diverts light sent by a light source backward against the propagation direction of the optical communication path. A photodiode receives the diverted light and measures its power level. The photodiode generates a feedback signal for the optical coupler and provides the feedback signal to the optical coupler. The optical coupler receives the feedback signal and adjusts a coupling alignment of the optical communication path to the optical fiber based on the feedback signal, which indicates the measured power level of the diverted counter-propagating light.

Abstract: In radio-frequency (RF) devices integrated on semiconductor-on-insulator (e.g., silicon-based) substrates, RF losses may be reduced by increasing the resistivity of the semiconductor device layer in the vicinity of (e.g., underneath and/or in whole or in part surrounding) the metallization structures of the RF device, such as, e.g., transmission lines, contacts, or bonding pads. Increased resistivity can be achieved, e.g., by ion-implantation, or by patterning the device layer to create disconnected semiconductor islands.

Abstract: Described herein are photonic systems and devices including a optical interface unit disposed on a bottom side of a photonic integrated circuit (PIC) to receive light from an emitter of the PIC. A top side of the PIC includes a flip-chip interface for electrically coupling the PIC to an organic substrate via the top side. An alignment feature corresponding to the emitter is formed with the emitter to be offset by a predetermined distance value; because the emitter and the alignment feature are formed using a shared processing operation, the offset (i.e., predetermined distance value) may be precise and consistent across similarly produced PICs. The PIC comprises a processing feature to image the alignment feature from the bottom side (e.g., a hole). A heat spreader layer surrounds the optical interface unit and is disposed on the bottom side of the PIC to spread heat from the PIC.

Abstract: A hybrid optical-electrical automated testing equipment (ATE) system can implement a workpress assembly that can interface with a device under test (DUT) and a load board that holds the DUT during testing, analysis, and calibration. A test hand can actuate to position the DUT on a socket and align one or more alignment features. The workpress assembly can include two optical interfaces that are optically coupled such that light can be provided to a side of the DUT that is facing away from the load board, thereby enabling the ATE system to perform simultaneous optical and electrical testing of the DUT.

Abstract: Described are various configurations for performing efficient optical and electrical testing of an opto-electrical device using a compact opto-electrical probe. The compact opto-electrical probe can include electrical contacts arranged for a given electrical contact layout of the opto-electrical device, and optical interface with a window in a probe core that transmits light from the opto-electrical device. An adjustable optical coupler of the probe can be mechanically positioned to receive light from the device's emitter to perform simultaneous optical and electrical analysis of the device.

Abstract: Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

Abstract: A hybrid automated testing equipment (ATE) system can simultaneously test electrical and optical components of a device under test, such as an optical transceiver. The device under test can be a multilane optical transceiver that transmits different channels of data on different lanes. The hybrid ATE system can include one or more light sources and optical switches in an optical test lane selector to selectively test and calibrate each optical and electrical components of each lane of the device under test.

Abstract: Temperature measurements of photonic circuit components may be performed optically, exploiting a temperature-dependent spectral property of the photonic device to be monitored itself, or of a separate optical temperature sensor placed in its vicinity. By facilitating measurements of the temperature of the individual photonic devices rather than merely the photonic circuit at large, such optical temperature measurements can provide more accurate temperature information and help improve thermal design.

Abstract: Described herein is a die-to-wafer bonding process that utilizes micro-transfer printing to transfer die from a source wafer onto an intermediate handle wafer. The resulting intermediate handle wafer structure can then be bonded die-down onto the target wafer, followed by removal of only the intermediate handle wafer, leaving the die in place bonded to the target wafer.

Abstract: Described are various configurations of optical structures having asymmetric-width waveguides. A photodetector can include parallel waveguides that have different widths, which can be connected via passive waveguide. One or more light absorbing regions can be proximate to the waveguides to absorb light propagating through one or more of the parallel waveguides. Multiple photodetectors having asymmetric width waveguides can operate to transduce light in different modes in a polarization diversity optical receiver.

Abstract: A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.

Abstract: An optical pick and place machine that includes a self-calibrating optical controller for error feedback based optical placement of optical components using active alignment is described. The optical controller can include a loopback mode to generate a baseline value of light generated by a light source and measured by a photodetector within the optical controller. The optical controller can further include an active alignment mode in which the light is coupled from the pick and place machine to the optical device on which the component is placed. The optical coupling of the placed component can be evaluated against the baseline value to ensure that the optical coupling is within specification (e.g., within a prespecified range).

Abstract: Described are various configurations of reduced crosstalk optical switches. Various embodiments can reduce or entirely eliminate crosstalk using a coupler that has a power-splitting ratio that compensates for amplitude imbalance caused by phase modulator attenuation. Some embodiments implement a plurality of phase modulators and couplers as part of a dilated switch network to increase overall bandwidth and further reduce potential for crosstalk.

Abstract: An optical modulator of an optical transceiver can be calibrated using intermediate frequency (IF) signals to generate accurate crossing point values (e.g., DC bias). A photodiode can measure output from the optical modulator at intermediate and high-speed frequencies to generate crossing point values that avoid crossing point errors. A target crossing point can be selected at any value (e.g., 40%, 50%) and bias values can be generated from IF signals and then stored in a lookup date for setting the modulator bias during operation.

Abstract: In photonic integrated circuits implemented in silicon-on-insulator substrates, non-conductive channels formed, in accordance with various embodiments, in the silicon device layer and/or the silicon handle of the substrate in regions underneath radio-frequency transmission lines of photonic devices can provide breaks in parasitic conductive layers of the substrate, thereby reducing radio-frequency substrate losses.

Abstract: An optical coupling device can couple incident light from a fiber into waveguides, but can reduce the coupling of return light from the waveguides into the fiber. A Faraday rotator layer can rotate by forty-five degrees, with a first handedness, respective planes of polarization of incident beams, and can rotate by forty-five degrees, with a second handedness opposite the first handedness, respective planes of polarization of return beams. A redirection layer can include at least one grating coupler that can redirect an incident beam of one polarization so that the redirected path extends within the redirection layer toward a first waveguide, and can redirect an incident beam of an opposite polarization so that the redirected path extends within the redirection layer toward a second waveguide. An optional birefringent layer can spatially separate incident beam having different polarizations, so that two single-polarization grating couplers can be used.