Abstract: A silicon photonic device includes a semiconductor structure and a silicon-based substrate. The substrate is bonded to the semiconductor structure and patterned to comprise a waveguide, a raised structure, and a chemical barrier structure. A channel is defined between the raised structure and the waveguide, such that the semiconductor structure encloses the channel in a first direction and defines a mouth of the channel. The mouth opening in a second direction perpendicular to the first direction. The chemical barrier structure is positioned to prevent ingress of liquid into at least a portion of the channel via the mouth.

Abstract: A device includes a semiconductor substrate, a light source displaced from the semiconductor substrate by a first displacement, a first dielectric waveguide displaced from the semiconductor substrate by a second displacement, and a second dielectric waveguide displaced from the semiconductor substrate by a third displacement. The second displacement is greater than the first displacement. The first dielectric waveguide overlaps at least a portion of the light source such that light is adiabatically coupled from the light source into the first dielectric waveguide. The third displacement is greater than the second displacement. The second dielectric waveguide overlaps at least a portion of the first dielectric waveguide such that light is coupled from the first dielectric waveguide into the second dielectric waveguide. The second dielectric waveguide includes an edge coupler configured to couple light out of the second dielectric waveguide.

Abstract: A photonic integrated circuit device can comprise one or more layers having different refraction indices that cause optical coupling issues and losses from layer variations. A film of material can be applied to a layer of the photonic integrated circuit to avoid the issues to increase the optical bandwidth of the photonic integrated circuit device and decrease sensitivity to manufacturing and design processes.

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: 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: 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.

Abstract: The wavelength response of an arrayed waveguide grating can be tuned, in accordance with various embodiments, using a beam sweeper including one or more heaters to shift a lateral position of light focused by the beam sweeper at an interface of the beam sweeper with an input free propagation region of the arrayed waveguide grating.

Abstract: A photonic integrated circuit device can comprise one or more layers having different refraction indices that cause optical coupling issues and losses from layer variations. A film of material can be applied to a layer of the photonic integrated circuit to avoid the issues to increase the optical bandwidth of the photonic integrated circuit device and decrease sensitivity to manufacturing and design processes.

Abstract: In integrated optical structures (e.g., silicon-to-silicon-nitride mode converters) implemented in semiconductor-on-insulator substrates, wire waveguides whose sidewalls substantially consist of portions coinciding with crystallographic planes and do not extend laterally beyond the top surface of the wire waveguide may provide benefits in performance and/or manufacturing needs. Such wire waveguides may be manufactured, e.g., using a dry-etch of the semiconductor device layer down to the insulator layer to form a wire waveguide with exposed sidewalls, followed by a smoothing crystallographic wet etch.

Abstract: Described are various configurations of integrated wavelength lockers including asymmetric Mach-Zehnder interferometers (AMZIs) and associated detectors. Various embodiments provide improved wavelength-locking accuracy by using an active tuning element in the AMZI to achieve an operational position with high locking sensitivity, a coherent receiver to reduce the frequency-dependence of the locking sensitivity, and/or a temperature sensor and/or strain gauge to computationally correct for the effect of temperature or strain changes.

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: Optical fabrication monitor structures can be included in a design fabricated on a wafer from a mask or fabrication reticle. A first set of components can be formed in an initial fabrication cycle, where the first set includes functional components and monitor structures. A second set of components can be formed by subsequent fabrication processes that can potentially cause errors or damage to the first set of components. The monitor structures can be implemented during fabrication (e.g., in a cleanroom) to detect fabrication errors without pulling or scrapping the 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: Optical fabrication monitor structures can be included in a design fabricated on a wafer from a mask or fabrication reticle. A first set of components can be formed in an initial fabrication cycle, where the first set includes functional components and monitor structures. A second set of components can be formed by subsequent fabrication processes that can potentially cause errors or damage to the first set of components. The monitor structures can be implemented during fabrication (e.g., in a cleanroom) to detect fabrication errors without pulling or scrapping the wafer.

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: 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.

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.

Abstract: The wavelength response of an arrayed waveguide grating can be tuned, in accordance with various embodiments, using a beam sweeper including one or more heaters to shift a lateral position of light focused by the beam sweeper at an interface of the beam sweeper with an input free propagation region of the arrayed waveguide grating.

Abstract: In integrated optical structures (e.g., silicon-to-silicon-nitride mode converters) implemented in semiconductor-on-insulator substrates, wire waveguides whose sidewalls substantially consist of portions coinciding with crystallographic planes and do not extend laterally beyond the top surface of the wire waveguide may provide benefits in performance and/or manufacturing needs. Such wire waveguides may be manufactured, e.g., using a dry-etch of the semiconductor device layer down to the insulator layer to form a wire waveguide with exposed sidewalls, followed by a smoothing crystallographic wet etch.

Abstract: The wavelength response of an arrayed waveguide grating can be tuned, in accordance with various embodiments, using a beam sweeper including one or more heaters to shift a lateral position of light focused by the beam sweeper at an interface of the beam sweeper with an input free propagation region of the arrayed waveguide grating.