Abstract: Methods and systems for monolithic integration of photonics and electronics in CMOS processes are disclosed and may include fabricating photonic and electronic devices on two CMOS wafers with different silicon layer thicknesses. The devices may be fabricated on semiconductor-on-insulator (SOI) wafers utilizing a bulk CMOS process and/or on a SOI wafer utilizing a SOI CMOS process. The different thicknesses may be fabricated utilizing a double SOI process and/or a selective area growth process. Cladding layers may be fabricated utilizing one or more oxygen implants and/or utilizing CMOS trench oxide on the CMOS wafer. Silicon may be deposited on the CMOS trench oxide utilizing epitaxial lateral overgrowth. Cladding layers may be fabricated utilizing selective backside etching. Reflective surfaces may be fabricated by depositing metal on the selectively etched regions. Silicon dioxide or silicon germanium integrated in the CMOS wafer may be utilized as an etch stop layer.

Abstract: Methods and systems for an optical coupler for photonics devices are disclosed and may include a photonics transceiver comprising a silicon photonics die and a fiber connector for receiving optical fibers and including a die coupler and an optical coupling element. The die coupler may be bonded to a top surface of the photonics die and aligned above an array of grating couplers. The optical coupling element may be attached to the die coupler and the electronics die and the source module may be bonded to the top surface of the photonics die. Modulated optical signals may be received in the photonics die from optical fibers coupled to the fiber connector.

Abstract: Methods and systems for a light source arrangement supporting direct coupling to a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed. The arrangement may include a laser, a microlens, a turning mirror, reciprocal and/or non-reciprocal polarization rotators, and an optical bench. The laser may generate an optical signal that may be focused utilizing the microlens. The optical signal may be reflected at an angle defined by the turning mirror, and may be transmitted out of the light source arrangement to one or more grating couplers in the chip. The laser may include a feedback insensitive laser. The light source arrangement may include two electro-thermal interfaces between the optical bench, the laser, and a lid affixed to the optical bench. The turning mirror may be integrated in a lid affixed to the optical bench or may be integrated in the optical bench.

Abstract: Methods and systems for stabilized directional couplers are disclosed and may include a system comprising first and second directional couplers formed by first and second waveguides, where one of the waveguides may comprise a length extender between the directional couplers. The directional couplers may be formed by reduced spacing between the waveguides on opposite sides of the length extender. An input optical signal may be communicated into one of the waveguides, where at least a portion of the input optical signal may be coupled between the waveguides in the first directional coupler and at least a portion of the coupled optical signal may be coupled between the waveguides in the second directional coupler. Optical signals may be communicated out of the system with magnitudes at a desired percentage of the input optical signal. The length extender may add phase delay for signals in one of the first and second waveguides.

Abstract: Methods and systems for optical alignment to a silicon photonically-enabled integrated circuit may include aligning an optical assembly to a photonics die comprising a transceiver by, at least, communicating optical signals from the optical assembly into a plurality of grating couplers in the photonics die, communicating the one or more optical signals from the plurality of grating couplers to optical taps, with each tap having a first output coupled to the transceiver and a second output coupled to a corresponding output grating coupler, and monitoring an output optical signal communicated out of said photonic chip via said output grating couplers. The monitored output optical signal may be maximized by adjusting a position of the optical assembly. The optical assembly may include an optical source assembly comprising one or more lasers or the optical assembly may comprise a fiber array. Such a fiber array may include single mode optical fibers.

Abstract: Methods and systems for optoelectronics transceivers of a CMOS chip are disclosed and may include receiving optical signals from optical fibers via grating couplers, which may include a guard ring. A CW optical signal may be received from a laser source via optical couplers, and may be modulated using optical modulators, which may be Mach-Zehnder and/or ring modulators. Circuitry in the CMOS chip may drive the optical modulators. The modulated optical signal may be communicated out of the CMOS chip into optical fibers via grating couplers. The received optical signals may be communicated between devices via waveguides. The photodetectors may include germanium waveguide photodiodes, avalanche photodiodes, and/or heterojunction diodes. The CW optical signal may be generated using an edge-emitting and/or a vertical-cavity surface emitting semiconductor laser.

Abstract: Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers may include an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path. The system may generate a pseudo-random bit sequence (PRBS) signal, generate an optical signal in the Tx path by applying the PRBS signal to a modulator, communicate the optical signal to the BIST loopback path and convert the optical signal to an electrical signal utilizing a photodetector, where the photodetector is a replica of a photodetector in the main Rx path, and assess the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be on a single complementary-metal oxide semiconductor (CMOS) die, or on two CMOS die where a first comprises electronic devices and a second comprises optical devices.

Abstract: Methods and systems for an optical coupler for photonics devices are disclosed and may include a photonics transceiver comprising a silicon photonics die and a fiber connector for receiving optical fibers and including a die coupler and an optical coupling element. The die coupler may be bonded to a top surface of the photonics die and aligned above an array of grating couplers. The optical coupling element may be attached to the die coupler and the electronics die and the source module may be bonded to the top surface of the photonics die. Modulated optical signals may be received in the photonics die from optical fibers coupled to the fiber connector.

Abstract: Methods and systems for coupling a light source assembly to an optical integrated circuit are disclosed and may include a system comprising a laser source assembly having a laser, a rotator, and a mirror, where the laser source assembly is coupled to a die including an angled grating coupler and a waveguide. The system may generate an optical signal utilizing the laser, rotate the polarization of the optical signal utilizing the rotator, reflect the rotated optical signal onto the grating coupler on the die, and couple the optical signal to the waveguide, where an angle between a grating coupler axis that is parallel to the waveguide and a plane of incidence of the optical signal reflected to the angled grating coupler is non-zero. The angle between the grating coupler axis and the plane of incidence of the optical signal reflected to the angled grating coupler may be 45 degrees.

Abstract: Methods and systems for an optical coupler for photonics devices are disclosed and may include a photonics transceiver comprising a silicon photonics die, an optical source module, and a fiber connector for receiving optical fibers and including a die coupler and an optical coupling element. The die coupler may be bonded to a top surface of the photonics die and aligned above an array of grating couplers. The optical coupling element may be attached to the die coupler and the electronics die and the source module may be bonded to the top surface of the photonics die. A continuous wave (CW) optical signal may be received in the photonics die from the optical source module. Modulated optical signals may be received in the photonics die from optical fibers coupled to the fiber connector.

Abstract: Methods and systems for optical alignment to a silicon photonically-enabled integrated circuit may include aligning an optical assembly to a photonics die comprising a transceiver by, at least, communicating optical signals from the optical assembly into a plurality of grating couplers in the photonics die, communicating the one or more optical signals from the plurality of grating couplers to optical taps, with each tap having a first output coupled to the transceiver and a second output coupled to a corresponding output grating coupler, and monitoring an output optical signal communicated out of said photonic chip via said output grating couplers. The monitored output optical signal may be maximized by adjusting a position of the optical assembly. The optical assembly may include an optical source assembly comprising one or more lasers or the optical assembly may comprise a fiber array. Such a fiber array may include single mode optical fibers.

Abstract: Methods and systems for optoelectronics transceivers of a CMOS chip are disclosed and may include receiving optical signals from optical fibers via grating couplers, which may include a guard ring. A CW optical signal may be received from a laser source via optical couplers, and may be modulated using optical modulators, which may be Mach-Zehnder and/or ring modulators. Circuitry in the CMOS chip may drive the optical modulators. The modulated optical signal may be communicated out of the CMOS chip into optical fibers via grating couplers. The received optical signals may be communicated between devices via waveguides. The photodetectors may include germanium waveguide photodiodes, avalanche photodiodes, and/or heterojunction diodes. The CW optical signal may be generated using an edge-emitting and/or a vertical-cavity surface emitting semiconductor laser.

Abstract: Methods and systems for coupling a light source assembly to an optical integrated circuit are disclosed and may include a system comprising a laser source assembly having a laser, a rotator, and a mirror, where the laser source assembly is coupled to a die including an angled grating coupler and a waveguide. The system may generate an optical signal utilizing the laser, rotate the polarization of the optical signal utilizing the rotator, reflect the rotated optical signal onto the grating coupler on the die, and couple the optical signal to the waveguide, where an angle between a grating coupler axis that is parallel to the waveguide and a plane of incidence of the optical signal reflected to the angled grating coupler is non-zero. The angle between the grating coupler axis and the plane of incidence of the optical signal reflected to the angled grating coupler may be 45 degrees.

Abstract: Methods and systems for stabilized directional couplers are disclosed and may include a system comprising first and second directional couplers formed by first and second waveguides, where one of the waveguides may comprise a length extender between the directional couplers. The directional couplers may be formed by reduced spacing between the waveguides on opposite sides of the length extender. An input optical signal may be communicated into one of the waveguides, where at least a portion of the input optical signal may be coupled between the waveguides in the first directional coupler and at least a portion of the coupled optical signal may be coupled between the waveguides in the second directional coupler. Optical signals may be communicated out of the system with magnitudes at a desired percentage of the input optical signal. The length extender may add phase delay for signals in one of the first and second waveguides.

Abstract: Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers may include an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path. The system may generate a pseudo-random bit sequence (PRBS) signal, generate an optical signal in the Tx path by applying the PRBS signal to a modulator, communicate the optical signal to the BIST loopback path and convert the optical signal to an electrical signal utilizing a photodetector, where the photodetector is a replica of a photodetector in the main Rx path, and assess the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be on a single complementary-metal oxide semiconductor (CMOS) die, or on two CMOS die where a first comprises electronic devices and a second comprises optical devices.

Abstract: A method and system for coupling optical signals into silicon optoelectronic chips are disclosed and may include coupling one or more optical signals into a back surface of a CMOS photonic chip comprising photonic, electronic, and optoelectronic devices. The devices may be integrated in a front surface of the chip and one or more optical couplers may receive the optical signals in the front surface of the chip. The optical signals may be coupled into the back surface of the chip via one or more optical fibers and/or optical source assemblies. The optical signals may be coupled to the grating couplers via a light path etched in the chip, which may be refilled with silicon dioxide. The chip may be flip-chip bonded to a packaging substrate. Optical signals may be reflected back to the grating couplers via metal reflectors, which may be integrated in dielectric layers on the chip.

Abstract: Methods and systems for monolithic integration of photonics and electronics in CMOS processes are disclosed and may include fabricating photonic and electronic devices on two CMOS wafers with different silicon layer thicknesses. The devices may be fabricated on semiconductor-on-insulator (SOI) wafers utilizing a bulk CMOS process and/or on a SOI wafer utilizing a SOI CMOS process. The different thicknesses may be fabricated utilizing a double SOI process and/or a selective area growth process. Cladding layers may be fabricated utilizing one or more oxygen implants and/or utilizing CMOS trench oxide on the CMOS wafer. Silicon may be deposited on the CMOS trench oxide utilizing epitaxial lateral overgrowth. Cladding layers may be fabricated utilizing selective backside etching. Reflective surfaces may be fabricated by depositing metal on the selectively etched regions. Silicon dioxide or silicon germanium integrated in the CMOS wafer may be utilized as an etch stop layer.

Abstract: Methods and systems for optical alignment to a silicon photonically-enabled integrated circuit may include aligning an optical assembly to a photonics die comprising a transceiver by, at least, communicating optical signals from the optical assembly into a plurality of grating couplers in the photonics die, communicating the one or more optical signals from the plurality of grating couplers to optical taps, with each tap having a first output coupled to the transceiver and a second output coupled to a corresponding output grating coupler, and monitoring an output optical signal communicated out of said photonic chip via said output grating couplers. The monitored output optical signal may be maximized by adjusting a position of the optical assembly. The optical assembly may include an optical source assembly comprising one or more lasers or the optical assembly may comprise a fiber array. Such a fiber array may include single mode optical fibers.

Abstract: Methods and systems for a light source arrangement supporting direct coupling to a photonically enabled complementary metal-oxide semiconductor (CMOS) chip are disclosed. The arrangement may include a laser, a microlens, a turning mirror, reciprocal and/or non-reciprocal polarization rotators, and an optical bench. The laser may generate an optical signal that may be focused utilizing the microlens. The optical signal may be reflected at an angle defined by the turning mirror, and may be transmitted out of the light source arrangement to one or more grating couplers in the chip. The laser may include a feedback insensitive laser. The light source arrangement may include two electro-thermal interfaces between the optical bench, the laser, and a lid affixed to the optical bench. The turning mirror may be integrated in a lid affixed to the optical bench or may be integrated in the optical bench.

Abstract: Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers are disclosed and may include, in an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path: generating a pseudo-random bit sequence (PRBS) signal, generating an optical signal in the Tx path by applying the PRBS signal to a modulator, communicating the optical signal to the BIST loopback path and converting to an electrical signal utilizing a photodetector, the photodetector being a replica of a photodetector in the main Rx path, and assessing the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be a single complementary-metal oxide semiconductor (CMOS) die or in two CMOS die, where a first comprises electronic devices and a second comprises optical devices.