Abstract: A method for fabricating an image sensor array having a first group of photodiodes for detecting light at visible wavelengths a second group of photodiodes for detecting light at infrared or near-infrared wavelengths, the method including forming a germanium-silicon layer for the second group of photodiodes on a first semiconductor donor wafer; defining a first interconnect layer on the germanium-silicon layer; defining integrated circuitry for controlling pixels of the image sensor array on a semiconductor carrier wafer; defining a second interconnect layer on the semiconductor carrier wafer; bonding the first interconnect layer with the second interconnect layer; defining the pixels of an image sensor array on a second semiconductor donor wafer; defining a third interconnect layer on the image sensor array; and bonding the third interconnect layer with the germanium-silicon layer.

Abstract: A circuit that includes: a photodiode configured to absorb photons and to generate photo-carriers from the absorbed photons; a first MOSFET transistor that includes: a first channel terminal coupled to a first terminal of the photodiode and configured to collect a portion of the photo-carriers generated by the photodiode; a second channel terminal; and a gate terminal coupled to a first control voltage source; a first readout circuit configured to output a first readout voltage; a second readout circuit configured to output a second readout voltage; and a current-steering circuit configured to steer the photo-carriers generated by the photodiode to one or both of the first readout circuit and the second readout circuit.

Abstract: A waveguide structure includes a first surface having a first width, a second surface having a second width, the second surface being opposite to the first surface, and a sidewall surface connecting the first surface and the second surface. The first width is greater than the second width.

Abstract: An optical apparatus including a semiconductor substrate; a first light absorption region supported by the semiconductor substrate, the first light absorption region including germanium and configured to absorb photons and to generate photo-carriers from the absorbed photons; a first layer supported by at least a portion of the semiconductor substrate and the first light absorption region, the first layer being different from the first light absorption region; one or more first switches controlled by a first control signal, the one or more first switches configured to collect at least a portion of the photo-carriers based on the first control signal; and one or more second switches controlled by a second control signal, the one or more second switches configured to collect at least a portion of the photo-carriers based on the second control signal, wherein the second control signal is different from the first control signal.

Abstract: A method for fabricating an optical sensor includes: forming, over a substrate, a first material layer comprising a first alloy of germanium and silicon having a first germanium composition; forming, over the first material layer, a graded material layer comprising germanium and silicon; and forming, over the graded material layer, a second material layer comprising a second alloy of germanium and silicon having a second germanium composition. The first germanium composition is lower than the second germanium composition and a germanium composition of the graded material layer is between the first germanium composition and the second germanium composition and varies along a direction perpendicular to the substrate.

Abstract: Structures and techniques introduced here enable the design and fabrication of photodetectors (PDs) and/or other electronic circuits using typical semiconductor device manufacturing technologies meanwhile reducing the adverse impacts on PDs' performance. Examples of the various structures and techniques introduced here include, but not limited to, a pre-PD homogeneous wafer bonding technique, a pre-PD heterogeneous wafer bonding technique, a post-PD wafer bonding technique, their combinations, and a number of mirror equipped PD structures. With the introduced structures and techniques, it is possible to implement PDs using typical direct growth material epitaxy technology while reducing the adverse impact of the defect layer at the material interface caused by lattice mismatch.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for eye gesture recognition. In one aspect, a method includes obtaining an electrical signal that represents a measurement, by a photodetector, of an optical signal reflected from an eye and determining a depth map of the eye based on phase differences between the electrical signal generated by the photodetector and a reference signal. Further, the method includes determining gaze information that represents a gaze of the eye based on the depth map and providing output data representing the gaze information.

Abstract: An optical apparatus including a semiconductor substrate; a first light absorption region supported by the semiconductor substrate, the first light absorption region including germanium and configured to absorb photons and to generate photo-carriers from the absorbed photons; a first layer supported by at least a portion of the semiconductor substrate and the first light absorption region, the first layer being different from the first light absorption region; one or more first switches controlled by a first control signal, the one or more first switches configured to collect at least a portion of the photo-carriers based on the first control signal; and one or more second switches controlled by a second control signal, the one or more second switches configured to collect at least a portion of the photo-carriers based on the second control signal, wherein the second control signal is different from the first control signal.

Abstract: Structures and techniques introduced here enable the design and fabrication of photodetectors (PDs) and/or other electronic circuits using typical semiconductor device manufacturing technologies meanwhile reducing the adverse impacts on PDs' performance. Examples of the various structures and techniques introduced here include, but not limited to, a pre-PD homogeneous wafer bonding technique, a pre-PD heterogeneous wafer bonding technique, a post-PD wafer bonding technique, their combinations, and a number of mirror equipped PD structures. With the introduced structures and techniques, it is possible to implement PDs using typical direct growth material epitaxy technology while reducing the adverse impact of the defect layer at the material interface caused by lattice mismatch.

Abstract: A circuit, including: a photodetector including a first readout terminal and a second readout terminal different than the first readout terminal; a first readout circuit coupled with the first readout terminal and configured to output a first readout voltage; a second readout circuit coupled with the second readout terminal and configured to output a second readout voltage; and a common-mode analog-to-digital converter (ADC) including: a first input terminal coupled with a first voltage source; a second input terminal coupled with a common-mode generator, the common-mode generator configured to receive the first readout voltage and the second readout voltage, and to generate a common-mode voltage between the first and second readout voltages; and a first output terminal configured to output a first output signal corresponding to a magnitude of a current generated by the photodetector.

Abstract: A photo-detecting apparatus includes an absorption layer configured to absorb photons and to generate photo-carriers from the absorbed photons, wherein the absorption layer includes germanium. A carrier guiding unit is electrically coupled to the absorption layer, wherein the carrier guiding unit includes a first switch including a first gate terminal.

Abstract: A circuit, including: a photodetector including a first readout terminal and a second readout terminal different than the first readout terminal; a first readout circuit coupled with the first readout terminal and configured to output a first readout voltage; a second readout circuit coupled with the second readout terminal and configured to output a second readout voltage; and a common-mode analog-to-digital converter (ADC) including: a first input terminal coupled with a first voltage source; a second input terminal coupled with a common-mode generator, the common-mode generator configured to receive the first readout voltage and the second readout voltage, and to generate a common-mode voltage between the first and second readout voltages; and a first output terminal configured to output a first output signal corresponding to a magnitude of a current generated by the photodetector.

Abstract: A photo-detecting apparatus includes a semiconductor substrate. A first germanium-based light absorption material is supported by the semiconductor substrate and configured to absorb a first optical signal having a first wavelength greater than 800 nm. A first metal line is electrically coupled to a first region of the first germanium-based light absorption material. A second metal line is electrically coupled to a second region of the first germanium-based light absorption material. The first region is un-doped or doped with a first type of dopants. The second region is doped with a second type of dopants. The first metal line is configured to control an amount of a first type of photo-generated carriers generated inside the first germanium-based light absorption material to be collected by the second region.

Abstract: An Si/Ge SACM avalanche photodiodes (APD) having low breakdown voltage characteristics includes an absorption region and a multiplication region having various layers of particular thicknesses and doping concentrations. An optical waveguide can guide infrared and/or optical signals or energy into the absorption region. The resulting photo-generated carriers are swept into the i-Si layer and/or multiplication region for avalanche multiplication. The APD has a breakdown bias voltage of well less than 12 V and an operating bandwidth of greater than 10 GHz, and is therefore suitable for use in consumer electronic devices, high speed communication networks, and the like.

Abstract: There is disclosed in one example a fiberoptic communication circuit for wavelength division multiplexing (WDM) communication, including: an incoming waveguide to receive an incoming WDM laser pulse; an intermediate slab including a demultiplexer circuit to isolate n discrete modes from the incoming WDM laser pulse; n outgoing waveguides to receive the n discrete modes, the outgoing waveguides including fully-etched rib-to-channel waveguides; and an array of n photodetectors to detect the n discrete modes.

Abstract: Structures and techniques introduced here enable the design and fabrication of photodetectors (PDs) and/or other electronic circuits using typical semiconductor device manufacturing technologies meanwhile reducing the adverse impacts on PDs' performance. Examples of the various structures and techniques introduced here include, but not limited to, a pre-PD homogeneous wafer bonding technique, a pre-PD heterogeneous wafer bonding technique, a post-PD wafer bonding technique, their combinations, and a number of mirror equipped PD structures. With the introduced structures and techniques, it is possible to implement PDs using typical direct growth material epitaxy technology while reducing the adverse impact of the defect layer at the material interface caused by lattice mismatch.

Abstract: An optical sensor including a first material layer comprising at least a first material; a second material layer comprising at least a second material that is different from the first material, where a material bandgap of the first material is larger than a material bandgap of the second material; and a graded material layer arranged between the first material layer and the second material layer, the graded material layer comprising an alloy of at least the first material and the second material having compositions of the second material that vary along a direction that is from the first material to the second material.

Abstract: A method for fabricating an image sensor array having a first group of photodiodes for detecting light at visible wavelengths a second group of photodiodes for detecting light at infrared or near-infrared wavelengths, the method including forming a germanium-silicon layer for the second group of photodiodes on a first semiconductor donor wafer; defining a first interconnect layer on the germanium-silicon layer; defining integrated circuitry for controlling pixels of the image sensor array on a semiconductor carrier wafer; defining a second interconnect layer on the semiconductor carrier wafer; bonding the first interconnect layer with the second interconnect layer; defining the pixels of an image sensor array on a second semiconductor donor wafer; defining a third interconnect layer on the image sensor array; and bonding the third interconnect layer with the germanium-silicon layer.

Abstract: An image sensor array including a carrier substrate; a first group of photodiodes coupled to the carrier substrate, where the first group of photodiodes include a first photodiode, and where the first photodiode includes a semiconductor layer configured to absorb photons at visible wavelengths and to generate photo-carriers from the absorbed photons; and a second group of photodiodes coupled to the carrier substrate, where the second group of photodiodes include a second photodiode, and where the second photodiode includes a germanium-silicon region fabricated on the semiconductor layer, the germanium-silicon region configured to absorb photons at infrared or near-infrared wavelengths and to generate photo-carriers from the absorbed photons.

Abstract: An optical sensor including a semiconductor substrate; a first light absorption region formed in the semiconductor substrate, the first light absorption region configured to absorb photons at a first wavelength range and to generate photo-carriers from the absorbed photons; a second light absorption region formed on the first light absorption region, the second light absorption region configured to absorb photons at a second wavelength range and to generate photo-carriers from the absorbed photons; and a sensor control signal coupled to the second light absorption region, the sensor control signal configured to provide at least a first control level and a second control level.