Abstract: Methods and systems for a low-parasitic silicon high-speed phase modulator are disclosed and may include fabricating an optical phase modulator that comprises a PN junction waveguide formed in a silicon layer, wherein the silicon layer may be on an oxide layer and the oxide layer may be on a silicon substrate. The PN junction waveguide may have p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide, and portions of the p-doped and n-doped regions may be removed. Contacts may be formed on remaining portions of the p-doped and n-doped regions. Portions of the p-doped and n-doped regions may be removed symmetrically about the PN junction waveguide. Portions of the p-doped and n-doped regions may be removed in a staggered fashion along the length of the PN junction waveguide. Etch transition features may be removed along the p-doped and n-doped regions.

Abstract: Methods and systems for a free space CWDM MUX/DEMUX for integration with a grating coupler based silicon platform may include an optical assembly coupled to a photonic chip. The optical assembly includes a lens array on the top surface of the chip, an angled mirror, a plurality of transparent spacers, and a plurality of thin film filters. The optical assembly may receive an input optical signal comprising a plurality of optical signals at different wavelengths via an optical fiber coupled to the optical assembly, communicate the plurality of optical signals through a first of the plurality of transparent spacers, pass a first of the plurality of optical signals through a corresponding one of the plurality of thin film filters while reflecting others of the plurality of optical signals back into the first of the plurality of transparent spacers, and reflect the others of the plurality of signals towards a second of the plurality of thin film filters.

Abstract: Methods and systems for a free space CWDM MUX/DEMUX for integration with a grating coupler based silicon platform may include an optical assembly comprising a lens array and a plurality of thin film filter splitters having angled reflective surfaces. The optical assembly may be operable to receive an input optical signal comprising a plurality of optical signals at different wavelengths via an optical fiber, focus the input optical signal onto a first thin film filter splitter, reflect a first of the optical signals into the lens array and passing others to a second thin film filter splitter, and reflect a second optical signal into the lens array and passing others to a third of the plurality of thin film filter splitters.

Abstract: A method and system for optoelectronic receivers utilizing waveguide heterojunction phototransistors (HPTs) integrated in a wafer are disclosed and may include receiving optical signals via optical fibers operably coupled to a top surface of the chip. Electrical signals may be generated utilizing HPTs that detect the optical signals. The electrical signals may be amplified via voltage amplifiers, or transimpedance amplifiers, the outputs of which may be utilized to bias the HPTs by a feedback network. The optical signals may be coupled into opposite ends of the HPTs. A collector of the HPTs may comprise a silicon layer and a germanium layer, a base may comprise a silicon germanium alloy with germanium composition ranging from 70% to 100%, and an emitter including crystalline or poly Si or SiGe. The optical signals may be demodulated by communicating a mixer signal to a base terminal of the HPTs.

Abstract: Methods and systems for selectively illuminated integrated photodetectors with configured launching and adaptive junction profile for bandwidth improvement may include a photonic chip comprising an input waveguide and a photodiode. The photodiode comprises an absorbing region with a p-doped region on a first side of the absorbing region and an n-doped region on a second side of the absorbing region. An optical signal is received in the absorbing region via the input waveguide, which is offset to one side of a center axis of the absorbing region; an electrical signal is generated based on the received optical signal. The first side of the absorbing region may be p-doped. P-doped and n-doped regions may alternate on the first and second sides of the absorbing region along the length of the photodiode. The absorbing region may comprise germanium, silicon, silicon/germanium, or similar material that absorbs light of a desired wavelength.

Abstract: Methods and systems for optical power monitoring of a light source coupled to a silicon integrated circuit (chip) are disclosed and may include, in a system comprising an optical source coupled to the chip: emitting a primary beam from a front facet of a laser in the optical source assembly and a secondary beam from a back facet of the laser, directing the primary beam to an optical coupler in the chip, directing the secondary beam to a surface-illuminated photodiode in the chip, and monitoring an output power of the laser utilizing an output signal from the photodiode. The primary beam may comprise an optical source for a photonics transceiver in the chip. The focused primary beam and the secondary beam may be directed to the chip using reflectors in a lid of the optical source.

Abstract: Methods and systems for a low-parasitic silicon high-speed phase modulator are disclosed and may include fabricating an optical phase modulator that comprises a PN junction waveguide formed in a silicon layer, wherein the silicon layer may be on an oxide layer and the oxide layer may be on a silicon substrate. The PN junction waveguide may have p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide, and portions of the p-doped and n-doped regions may be removed. Contacts may be formed on remaining portions of the p-doped and n-doped regions. Portions of the p-doped and n-doped regions may be removed symmetrically about the PN junction waveguide. Portions of the p-doped and n-doped regions may be removed in a staggered fashion along the length of the PN junction waveguide. Etch transition features may be removed along the p-doped and n-doped regions.

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.

Abstract: Methods and systems for a connectionless integrated optical receiver and transmitter test are disclosed and may include an optoelectronic transceiver comprising a transmit (Tx) path and a receive (Rx) path, with each path comprising optical switches. The transceiver may be operable to: generate a first modulated optical signal utilizing a modulator in the Tx path, couple the first modulated optical signal to a first optical switch in the Rx path via a second optical switch in the Tx path when the optoelectronic transceiver is configured in a self-test mode, receive a second modulated optical signal via a grating coupler in the Rx path when the optoelectronics transceiver is configured in an operational mode, and communicate the second modulated optical signal to a photodetector in the Rx path via the first optical switch. The first modulated optical signal may be communicated to a grating coupler in the Tx path via the second optical switch.

Abstract: Methods and systems for a silicon-based optical phase modulator with high modal overlap are disclosed and may include, in an optical modulator having a rib waveguide in which a cross-shaped depletion region separates four alternately doped sections: receiving an optical signal at one end of the optical modulator, modulating the received optical signal by applying a modulating voltage, and communicating a modulated optical signal out of an opposite end of the modulator. The modulator may be in a silicon photonically-enabled integrated circuit which may be in a complementary-metal oxide semiconductor (CMOS) die. An optical mode may be centered on the cross-shaped depletion region. The four alternately doped sections may include: a shallow depth p-region, a shallow depth n-region, a deep p-region, and a deep n-region. The shallow depth p-region may be electrically coupled to the deep p-region periodically along the length of the modulator.

Abstract: Methods and systems for a low-parasitic silicon high-speed phase modulator are disclosed and may include fabricating an optical phase modulator that comprises a PN junction waveguide formed in a silicon layer, wherein the silicon layer may be on an oxide layer and the oxide layer may be on a silicon substrate. The PN junction waveguide may have p-doped and n-doped regions on opposite sides along a length of the PN junction waveguide, and portions of the p-doped and n-doped regions may be removed. Contacts may be formed on remaining portions of the p-doped and n-doped regions. Portions of the p-doped and n-doped regions may be removed symmetrically about the PN junction waveguide. Portions of the p-doped and n-doped regions may be removed in a staggered fashion along the length of the PN junction waveguide. Etch transition features may be removed along the p-doped and n-doped regions.

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.

Abstract: Methods and systems for a connectionless integrated optical receiver and transmitter test are disclosed and may include an optoelectronic transceiver comprising a transmit (Tx) path and a receive (Rx) path, with each path comprising optical switches. The transceiver may be operable to: generate a first modulated optical signal utilizing a modulator in the Tx path, couple the first modulated optical signal to a first optical switch in the Rx path via a second optical switch in the Tx path when the optoelectronic transceiver is configured in a self-test mode, receive a second modulated optical signal via a grating coupler in the Rx path when the optoelectronics transceiver is configured in an operational mode, and communicate the second modulated optical signal to a photodetector in the Rx path via the first optical switch. The first modulated optical signal may be communicated to a grating coupler in the Tx path via the second optical switch.

Abstract: Methods and systems for a vertical junction high-speed phase modulator are disclosed and may include a semiconductor device having a semiconductor waveguide including a slab section, a rib section extending above the slab section, and raised ridges extending above the slab section on both sides of the rib section. The semiconductor device has a vertical pn junction with p-doped material and n-doped material arranged vertically with respect to each other in the rib and slab sections. The rib section may be either fully n-doped or p-doped in each cross-section along the semiconductor waveguide. Electrical connection to the p-doped and n-doped material may be enabled by forming contacts on the raised ridges, and electrical connection may be provided to the rib section from one of the contacts via periodically arranged sections of the semiconductor waveguide, where a cross-section of both the rib section and the slab section in the periodically arranged sections may be fully n-doped or fully p-doped.

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 optical power monitoring of a light source coupled to a silicon integrated circuit (chip) are disclosed and may include, in a system comprising an optical source coupled to the chip: emitting a primary beam from a front facet of a laser in the optical source assembly and a secondary beam from a back facet of the laser, directing the primary beam to an optical coupler in the chip, directing the secondary beam to a surface-illuminated photodiode in the chip, and monitoring an output power of the laser utilizing an output signal from the photodiode. The primary beam may comprise an optical source for a photonics transceiver in the chip. The focused primary beam and the secondary beam may be directed to the chip using reflectors in a lid of the optical source.

Abstract: Methods and systems for integrated multi-port waveguide photodetectors are disclosed and may include an optical receiver on a chip, where the optical receiver comprises a multi-port waveguide photodetector having three or more input ports. The optical receiver may be operable to receive optical signals via one or more grating couplers, couple optical signals to the photodetector via optical waveguides in the chip, and generate an output electrical signal based on the coupled optical signals using the photodetector. The photodetector may include four ports coupled to two PSGCs. The optical signals may be coupled to the photodetector via S-bends and/or tapers at ends of the optical waveguides. A width of the photodetector on sides that are coupled to the optical waveguides may be wider than a width of the optical waveguides coupled to the sides. Optical signals may be mixed with local oscillator signals using the multi-port waveguide photodetector.

Abstract: Methods and systems for optical power monitoring of a light source assembly coupled to a silicon photonically-enabled integrated circuit (chip) are disclosed and may include, in a system comprising an optical source assembly coupled to the chip: emitting a primary beam from a front facet of a laser in the optical source assembly and a secondary beam from a back facet of the laser, directing the primary beam to an optical coupler in the chip, directing the secondary beam to a surface-illuminated photodiode in the chip, and monitoring an output power of the laser utilizing an output signal from the photodiode. The primary beam may comprise an optical source for a photonics transceiver in the chip. The focused primary beam and the secondary beam may be directed to the chip using reflectors in a lid of the optical source assembly.

Abstract: Methods and systems for a connectionless integrated optical receiver and transmitter test are disclosed and may include an optoelectronic transceiver comprising a transmit (Tx) path and a receive (Rx) path, with each path comprising optical switches. The transceiver may be operable to: generate a first modulated optical signal utilizing a modulator in the Tx path, couple the first modulated optical signal to a first optical switch in the Rx path via a second optical switch in the Tx path when the optoelectronic transceiver is configured in a self-test mode, receive a second modulated optical signal via a grating coupler in the Rx path when the optoelectronics transceiver is configured in an operational mode, and communicate the second modulated optical signal to a photodetector in the Rx path via the first optical switch. The first modulated optical signal may be communicated to a grating coupler in the Tx path via the second optical switch.

Abstract: A method and system for optoelectronic receivers utilizing waveguide heterojunction phototransistors (HPTs) integrated in a wafer are disclosed and may include receiving optical signals via optical fibers operably coupled to a top surface of the chip. Electrical signals may be generated utilizing HPTs that detect the optical signals. The electrical signals may be amplified via voltage amplifiers, or transimpedance amplifiers, the outputs of which may be utilized to bias the HPTs by a feedback network. The optical signals may be coupled into opposite ends of the HPTs. A collector of the HPTs may comprise a silicon layer and a germanium layer, a base may comprise a silicon germanium alloy with germanium composition ranging from 70% to 100%, and an emitter including crystalline or poly Si or SiGe. The optical signals may be demodulated by communicating a mixer signal to a base terminal of the HPTs.