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: Described herein are methods, systems, and apparatuses to utilize shielding regions formed in photonic integrated circuits (PICs). Portions of layers of a PIC are selectively removed, and optionally, replaced with another material. These regions are formed to block stray light from interacting with optical components of the PIC, and therefore can prevent optical crosstalk and/or noise. Metal or another absorption/reflective material can be deposited in the place of the removed layer portions of the PIC to absorb or reflect light. Additionally, by depositing metal, RF isolation can be achieved by forming a ground plane, by forming a ground trace that shields a signal trace in an RF transmission line, or by placing a conductor which terminates electric fields between sensitive RF receivers and adjacent RF elements. Additionally the process operations required to perform isolation can also be used to change the thermal conductivity of devices and regions on a PIC.

Abstract: Embodiments describe bi-directional AWGs comprising a first input waveguide coupled to a first free propagation region to input light into a dispersive waveguide array, a second input waveguide coupled to a second free propagation region to input light into the dispersive waveguide array, a first plurality of output waveguides coupled to the first free propagation region to output light from the dispersive waveguide array received from the second input waveguide, and a second plurality of output waveguides coupled to the second free propagation region to output light from the dispersive waveguide array received from the first input waveguide. At least one of these FPRs reduces potential crosstalk received at their respective output waveguides by having at least one of their input waveguides or plurality of output waveguides angled offset from a center of the dispersive waveguide array to attenuate carrier waves that can be present at the output waveguides.

Abstract: Embodiments of the invention describe apparatuses, systems, and methods of thermal management for photonic integrated circuits (PICs). Embodiments include a first device and a second device comprising including waveguides, wherein the first and second devices have different thermal operating conditions. A first region is adjacent to a waveguide of the first device, wherein its optical mode is to be substantially confined by the first region, and wherein the first region has a first thermal conductivity to dissipate heat based on the thermal operating condition of the first device. A second region is adjacent to a waveguide of the second device, wherein its optical mode is to be substantially confined by the second region, and wherein the second region has a second thermal conductivity to dissipate heat based on the thermal operating condition of the second device. In some embodiments, thermal cross talk is reduced without significantly affecting optical performance.

Abstract: Described herein are methods, systems, and apparatuses to utilize a laser device comprising a gain section, a wavelength filter, a first reflector, and a second reflector to form a laser cavity with the first reflector, the laser cavity to include the gain section and the wavelength filter. The wavelength filter is temperature stabilized to a predetermined temperature range and the remaining portions of the laser cavity are not temperature stabilized. The wavelength filter, when at the predetermined temperature range, comprises a plurality of adjacent longitudinal modes such that a difference in modal gain values associated with each of the adjacent longitudinal modes is within a predetermined delta. Thus, the cavity of the laser device is designed to experience some mode hops when the device temperature changes; however, because the wavelength filter is stabilized in temperature, the cavity drift due to these mode hops is within a limited range.

Abstract: Embodiments of the invention describe photonic integrated circuits (PICs) formed using simultaneous fabrication operations performed on photonic device layers. Each device of a PIC may be made from different optimized materials by growing the materials separately, cutting pieces of the different materials and bonding these pieces to a shared wafer. Embodiments of the invention bond photonic device layers so that shared (i.e., common) processing operations may be utilized to make more than one device simultaneously. Embodiments of the invention allow for simpler, more cost effective fabrication of PICs and improve photonic device performance and reliability.

Abstract: Embodiments describe optical devices including a first waveguide, comprising a first cross-sectional area, to receive a light comprising a first optical mode, and a second waveguide, adjacent to the first waveguide, to receive a light comprising a second optical mode orthogonal to the first optical mode. The second waveguide comprises a second cross-sectional area different than the first waveguide such that an absorption/gain coefficient of the second waveguide for light comprising the second optical mode is equal to an absorption/gain coefficient of the first waveguide for light comprising the first optical mode. The optical devices may comprise modulators, photodetectors, or semiconductor optical amplifiers (SOAs).

Abstract: Embodiments of the invention describe heterogeneous photonic integrated circuits (PIC) wherein a first silicon region is separated from the heterogeneous semiconductor material by a first distance, and a second silicon region is separated from the heterogeneous semiconductor material by a second distance greater than the first distance. Thus embodiments of the invention may be described as, in heterogeneous regions of a heterogeneous PIC, silicon waveguides using multiple heights of the silicon waveguide, or other structures with multiple offset heights between silicon and heterogeneous materials (as described herein).

Abstract: Embodiments of the invention describe systems, apparatuses and methods for providing athermicity and a tunable spectral response for optical filters. Finite impulse response (FIR) filters are commonly implemented in photonic integrated circuits (PICs) to make devices such as wavelength division multiplexing (WDM) devices, asymmetric Mach-Zehnder interferometers (AMZIs) and array waveguide gratings (AWGs). Athermicity of an FIR filter describes maintaining a consistent frequency transmission spectrum as the ambient temperature changes. A tunable spectral response for an FIR filter describes changing the spectrum of an FIR filter based on its application, as well as potentially correcting for fabrication deviations from the design. In addition, embodiments of the invention reduce energy dissipation requirements and control complexity compared to prior art solutions.

Abstract: Embodiments of the invention describe (M)MPICs, which include RF processing components and heterogeneous silicon photonic components that include a first region of silicon material and a second region of non-silicon material with high electro-optic efficiency (e.g., III-V material). Said heterogeneous silicon components are fabricated from the silicon and non-silicon material, and therefore may be interconnected via silicon/non-silicon waveguides formed from the above described regions of silicon/non-silicon material. The effect of interconnecting these components via said optical waveguides is that an RF signal may be processed using photonic components consistent with the size of an MMIC, without the need for any optical fibers; therefore, embodiments of the invention describe a chip scale microwave IC that has the broad optical bandwidth of photonics without any optical interfaces to fiber.

Abstract: Described herein are methods, systems, and apparatuses to utilize a laser device comprising a gain section, a wavelength filter, a first reflector, and a second reflector to form a laser cavity with the first reflector, the laser cavity to include the gain section and the wavelength filter. The wavelength filter is temperature stabilized to a predetermined temperature range and the remaining portions of the laser cavity are not temperature stabilized. The wavelength filter, when at the predetermined temperature range, comprises a plurality of adjacent longitudinal modes such that a difference in modal gain values associated with each of the adjacent longitudinal modes is within a predetermined delta. Thus, the cavity of the laser device is designed to experience some mode hops when the device temperature changes; however, because the wavelength filter is stabilized in temperature, the cavity drift due to these mode hops is within a limited range.

Abstract: Embodiments of the invention describe a modulator material heterogeneous-bonded over a resonator structure in a photonic integrated circuit (PIC) to create a resonance-enhanced modulator. The resulting structure may utilize optimal materials and optimized fabrication processes to create a device with the desired properties. Materials and processes used may combine advantages such as high index contrast, low propagation loss, small resonator volume, efficient modulation combined with desired linearity or nonlinearity, and precisely fabricated evanescent and interferometric couplers. The materials can be combined flexibly to create a resonator with a wide range of Free Spectral Range (FSR), cavity Q-factor, and modulation efficiency, allowing for resonance enhanced modulators to be designed optimally for a range of requirements.

Abstract: Embodiments of the invention describe photonic integrated circuits (PICs) for accomplishing polarization splitting and rotation. Embodiments of the invention include a first waveguide to receive light comprising orthogonally polarized transverse electric (TE) and transverse magnetic (TM) modes, and a second waveguide disposed below the first waveguide and comprising a reverse taper-shaped side to adiabatically receive one of the polarization modes (e.g., the TE mode) of the received light from the first waveguide. Said horizontal offset between the first and the reverse taper-shaped side of the second waveguide comprises an offset such that, for example, the TM mode of the received light is rotated to a TE mode in the first waveguide. The above described offsets and taper shaped structures may also be used in an optical combiner.

Abstract: Embodiments of the invention describe various configurations for a multi-wavelength laser cavity. A laser cavity may include a shared reflector and a plurality of reflectors. Each of the plurality of reflectors and the shared reflector together form one of the plurality of output wavelength channels. A shared filter is utilized to filter the optical signal of the laser cavity to comprise a subset of a plurality of cavity modes. A (de)multiplexer, comprising a plurality of filtering elements), receives the optical signal and further selects and separates the final lasing wavelengths from the selected subset of cavity modes, and each filtering element outputs an optical signal having a wavelength for one of the output wavelength channels.

Abstract: Embodiments describe transceiver architectures to enable ‘loopback’ operation, thereby allowing or on-chip or intra module characterization of the transceiver. This includes but is not limited to tests such as bit error rate (BER) characterization, received power characterization and calibration of filters (MUX, DMUX etc.) present in the transceiver. Embodiments may also describe architectures for superimposing low-speed data on to the signal coming out of a transmitter, which in turn enables low frequency communication between network elements in the external link.

Abstract: Embodiments of the invention describe substrates, used to form optical devices, which include high thermal conductivity intermediate layers. Said substrates comprise a bulk layer, an optical device layer comprising a first material, and an intermediate layer disposed between the bulk layer and the device layer comprising a second material having a higher thermal conductivity and a lower index of refraction than the first material. In the resulting devices, said intermediate layer functions as part of the device layer structure—i.e., provides optical or electrical power dissipation (i.e. thermal) functionality for the device formed from said substrate. Thus, optical devices do not necessarily need to utilize an add-on packaging solution for heat absorption when formed from substrate stacks according to embodiments of the invention.

Abstract: Embodiments of the invention utilize optical structures created by processes in the wafer fabrication foundry to form optical isolators and circulators. Grating coupling structures are utilized to couple light having a chosen polarization component into free space through non-reciprocal rotation material; said light is captured by another set of grating coupling structures after experiencing a 45 degree rotation of the polarization. By non-reciprocally rotating the polarization, the input and output ports of the optical isolator will be different depending on the direction of the light propagation. The amount of non-reciprocal rotation material utilized by embodiments of the invention may be small, and the grating coupling structures may be efficiently made to couple to each other as their field profiles may be matched and their position may be precisely defined by lithographic means.

Abstract: Embodiments of the invention describe a skew directional coupler for a plurality of waveguides. Said coupler includes a first waveguide on a first plane and a second waveguide on a second plane separate from the first plane. In embodiments of the invention, the first waveguide is disposed on top of the second waveguide to form an overlapping region of a segment of the first waveguide and a segment of the second waveguide, wherein an optical axis of the segment of the first waveguide is horizontally skew to an optical axis of the segment of the second waveguide, and wherein light is to be passively transmitted between the first and second waveguide segments via mode hybridization.

Abstract: Embodiments of the invention describe heterogeneous photonic integrated circuits (PIC) wherein a first silicon region is separated from the heterogeneous semiconductor material by a first distance, and a second silicon region is separated from the heterogeneous semiconductor material by a second distance greater than the first distance. Thus embodiments of the invention may be described as, in heterogeneous regions of a heterogeneous PIC, silicon waveguides using multiple heights of the silicon waveguide, or other structures with multiple offset heights between silicon and heterogeneous materials (as described herein).

Abstract: Embodiments of the invention describe integrating a phase shifting component into a cavity of a laser. Said phase shifter is capable of a continuous phase shift at a single wavelength over a large range (where the maximum energy consumption of the phase shifting component does not scale with the phase shifting range). In other words, said phase shifter is used to form a configurable optical cavity length for a laser. Embodiments of the invention thus utilize a plurality of optical cavity lengths—including one or more optical cavity lengths to potentially shift the phase of the output optical signal, to maintain a laser cavity's output wavelength and avoid spatial mode-hops in the presence of fluctuations such as temperature drift or changes to the drive current of the laser.