Abstract: Implementations are directed to configurable intensity-modulation direct-detection (IM-DD) optical transceivers that are configurable between single-polarization (SP) operation and dual-polarization (DP) operation.

Abstract: An optical input/output (I/O) system includes at least one electronic circuit die on at least one first substrate on a first side of a printed circuit board (PCB), where the at least one electronic circuit die includes at least 4 electrical inputs and at least 4 electrical outputs that are each configured to operate with a speed of at least 10 Gb/s. The optical I/O system also includes at least one photonic circuit die on at least one second substrate on a second side of the PCB, opposite the first side of the PCB. A plurality of electrical connections are implemented through the PCB, and electrically connect the at least one photonic circuit die with the at least 4 electrical inputs and the at least 4 electrical outputs of the at least one electronic circuit die.

Abstract: An optical system includes a first modulator configured to: receive first input light, modulate an amplitude of the first input light with a first data signal, modulate a phase of the first input light with a first marker signal, and output to an optical element, as first modulated light, the first input light modulated with the first data signal and the first marker signal. The optical system includes a second modulator configured to: receive second input light, modulate an amplitude of the second input light with a second data signal, modulate a phase of the second input light with a second marker signal, and output to the optical element, as second modulated light, the second input light modulated with the second data signal and the second marker signal. The second marker signal includes a complementary version of the first marker signal.

Abstract: A silicon-photonic optical modulator includes at least one optical input and at least one optical waveguide that is connected to the at least one optical input. The at least one optical waveguide is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light, where each of the at least one optical waveguide is configured as a rib waveguide that includes a rib arranged on a slab. The silicon-photonic optical modulator also includes at least one electrode configured to apply at least one electric field to the quasi-TM polarized light in the at least one optical waveguide. In some implementations, a height of the rib waveguide is greater than 0.85 ?/n, where ? is a free-space wavelength of light and n is a refractive index of silicon in the silicon-photonic optical modulator, and a width of the rib waveguide is greater than a thickness of the slab.

Abstract: A silicon-photonic optical modulator includes at least one optical input and at least one optical waveguide that is connected to the at least one optical input. The at least one optical waveguide is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light, where each of the at least one optical waveguide is configured as a rib waveguide that includes a rib arranged on a slab. The silicon-photonic optical modulator also includes at least one electrode configured to apply at least one electric field to the quasi-TM polarized light in the at least one optical waveguide. In some implementations, a height of the rib waveguide is greater than 0.85 ?/n, where ? is a free-space wavelength of light and n is a refractive index of silicon in the silicon-photonic optical modulator, and a width of the rib waveguide is greater than a thickness of the slab.

Abstract: A dual-polarization (DP) intensity-modulated direct detection (IMDD) receiver includes: an input port configured to receive input light; an optical 2×2 multi-input-multi-output (MIMO) demultiplexer configured to receive light from a first optical transmission path and a second optical transmission path and perform optical 2×2 MIMO polarization demultiplexing; a pair of photodetectors configured to detect outputs at a common carrier frequency; and an electrical 2×2 MIMO demultiplexer configured to receive a signal from the first electrical transmission path and a signal from the second electrical transmission path and perform electrical 2×2 MIMO polarization demultiplexing to output a first demultiplexed signal and a second demultiplexed signal.

Abstract: A silicon-photonic optical modulator includes an optical input; and an optical waveguide that is connected to the optical input and that is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light. The optical waveguide is configured as a rib waveguide that includes a rib arranged on a slab. The rib includes at least one dopant. An average concentration of the at least one dopant in a vertical doping profile in a lowermost portion of the rib is larger than an average concentration of the at least one dopant in the vertical doping profile in an uppermost portion of the rib. The uppermost portion of the rib has a height that is between 20% and 80% of a height of the rib waveguide. The lowermost portion of the rib includes a remainder of the rib below the uppermost portion.

Abstract: An optical multiple-input-multiple-output (MIMO) receiver includes an input port configured to receive input light; a Stokes measurement apparatus configured to generate measurements of Stokes parameters; an optical MIMO demultiplexer configured to generate a plurality of demultiplexed output light signals based on (i) the input light and (ii) the measurements of the Stokes parameters generated by the Stokes measurement apparatus; and a plurality of output ports configured to output the plurality of demultiplexed output light signals generated by the optical MIMO demultiplexer. In particular, the Stokes measurement apparatus is connected to the optical MIMO demultiplexer in a parallel arrangement.

Abstract: An optical device includes an input port configured to receive pumping light; an optical splitter configured to split the pumping light into a plurality of waveguides; and a plurality of semiconductor optical amplifiers (SOAs) implemented on a single III-V die. Each SOA is configured to be optically pumped by receiving a portion of the pumping light from a respective one of the plurality of waveguides.

Abstract: A silicon-photonic optical modulator includes at least one optical input and at least one optical waveguide that is connected to the at least one optical input. The at least one optical waveguide is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light, where each of the at least one optical waveguide is configured as a rib waveguide that includes a rib arranged on a slab. The silicon-photonic optical modulator also includes at least one electrode configured to apply at least one electric field to the quasi-TM polarized light in the at least one optical waveguide. In some implementations, a height of the rib waveguide is greater than 0.85 ?/n, where ? is a free-space wavelength of light and n is a refractive index of silicon in the silicon-photonic optical modulator, and a width of the rib waveguide is greater than a thickness of the slab.

Abstract: A 2×2 optical multi-input-multi-output (MIMO) demultiplexer is disclosed. A first optical phase shifter applies a first relative phase shift between a first pair of optical transmission paths that are received from MIMO inputs, and a first 2×2 optical coupler combines the first pair of optical transmission paths and outputs a second pair of optical transmission paths. A second optical phase shifter applies a second relative phase shift between the second pair of optical transmission paths, and a second 2×2 optical coupler combines the second pair of optical transmission paths and outputs a third pair of optical transmission paths. A third optical phase shifter applies a third relative phase shift between the third pair of optical transmission paths, and a third 2×2 optical coupler combines the third pair of optical transmission paths and outputs a fourth pair of optical transmission paths, which are output by a pair of MIMO outputs.

Abstract: A dual-polarization (DP) intensity-modulated direct detection (IMDD) receiver includes an input port configured to receive input light; an optical polarization splitter configured to split the input light into a pair of optical transmission paths; a pair of photodetectors including (i) a first photodetector configured to detect light at a first carrier frequency and output an electrical signal into a first electrical transmission path, (ii) a second photodetector configured to detect light at a second carrier frequency and output an electrical signal into a second electrical transmission path, wherein the first carrier frequency and the second carrier frequency are separated by a frequency difference; and an electrical 2×2 multi-input-multi-output (MIMO) polarization demultiplexer configured to input the first electrical transmission path and the second electrical transmission path and perform electrical 2×2 MIMO polarization demultiplexing to output a first demultiplexed signal and a second demultiplexed sig

Abstract: An optical modulator includes a Mach-Zehnder interferometer including (i) a first optical waveguide including a first semiconductor junction diode, and (ii) a second optical waveguide including a second semiconductor junction diode. A semiconductor region connects the first and second semiconductor junction diodes such that a distance between the first and second optical waveguides is less than 2.0 ?m for at least a portion of a longitudinal direction of the optical modulator. In another aspect, a method of modulating an optical signal includes splitting input light into first and second optical transmission paths; modulating a phase difference between light in the first optical transmission path and light in the second optical transmission path without applying a bias voltage through an impedance less than 100 ohm between the first and second optical transmission paths; and combining light that is output from the first and second optical transmission paths.

Abstract: A 2×2 optical multi-input-multi-output (MIMO) demultiplexer is disclosed. A first optical phase shifter applies a first relative phase shift between a first pair of optical transmission paths that are received from MIMO inputs, and a first 2×2 optical coupler combines the first pair of optical transmission paths and outputs a second pair of optical transmission paths. A second optical phase shifter applies a second relative phase shift between the second pair of optical transmission paths, and a second 2×2 optical coupler combines the second pair of optical transmission paths and outputs a third pair of optical transmission paths. A third optical phase shifter applies a third relative phase shift between the third pair of optical transmission paths, and a third 2×2 optical coupler combines the third pair of optical transmission paths and outputs a fourth pair of optical transmission paths, which are output by a pair of MIMO outputs.

Abstract: An optical modulator includes a Mach-Zehnder interferometer including (i) a first optical waveguide including a first semiconductor junction diode, and (ii) a second optical waveguide including a second semiconductor junction diode. A semiconductor region connects the first and second semiconductor junction diodes such that a distance between the first and second optical waveguides is less than 2.0 ?m for at least a portion of a longitudinal direction of the optical modulator. In another aspect, a method of modulating an optical signal includes splitting input light into first and second optical transmission paths; modulating a phase difference between light in the first optical transmission path and light in the second optical transmission path without applying a bias voltage through an impedance less than 100 ohm between the first and second optical transmission paths; and combining light that is output from the first and second optical transmission paths.

Abstract: An optical multiple-input-multiple-output (MIMO) receiver includes an input port configured to receive input light; a Stokes measurement apparatus configured to generate measurements of Stokes parameters; an optical MIMO demultiplexer configured to generate a plurality of demultiplexed output light signals based on (i) the input light and (ii) the measurements of the Stokes parameters generated by the Stokes measurement apparatus; and a plurality of output ports configured to output the plurality of demultiplexed output light signals generated by the optical MIMO demultiplexer. In particular, the Stokes measurement apparatus is connected to the optical MIMO demultiplexer in a parallel arrangement.

Abstract: A silicon-photonic optical modulator includes at least one optical input and at least one optical waveguide that is connected to the at least one optical input. The at least one optical waveguide is configured to propagate quasi-transverse-magnetic (quasi-TM) polarized light, where each of the at least one optical waveguide is configured as a rib waveguide that includes a rib arranged on a slab. The silicon-photonic optical modulator also includes at least one electrode configured to apply at least one electric field to the quasi-TM polarized light in the at least one optical waveguide. In some implementations, a height of the rib waveguide is greater than 0.85?/n, where ? is a free-space wavelength of light and n is a refractive index of silicon in the silicon-photonic optical modulator, and a width of the rib waveguide is greater than a thickness of the slab.

Abstract: An optical modulator includes a Mach-Zehnder interferometer including (i) a first optical waveguide including a first semiconductor junction diode, and (ii) a second optical waveguide including a second semiconductor junction diode. A semiconductor region connects the first and second semiconductor junction diodes such that a distance between the first and second optical waveguides is less than 2.0 ?m for at least a portion of a longitudinal direction of the optical modulator. In another aspect, a method of modulating an optical signal includes splitting input light into first and second optical transmission paths; modulating a phase difference between light in the first optical transmission path and light in the second optical transmission path without applying a bias voltage through an impedance less than 100 ohm between the first and second optical transmission paths; and combining light that is output from the first and second optical transmission paths.

Abstract: A multi-wavelength dual-polarization (DP) receiver includes an input port configured to receive input light; an optical polarization splitter and rotator configured to split the input light into a first optical waveguide and a second optical waveguide; a first wavelength demultiplexer connected to the first optical waveguide and configured to output wavelength-demultiplexed light into a first plurality of optical waveguides; a second wavelength demultiplexer connected to the second optical waveguide and configured to output wavelength-demultiplexed light into a second plurality of optical waveguides; and a plurality of optical multi-input-multi-output (MIMO) polarization demultiplexers, each of which is connected to a respective one of the first plurality of optical waveguides and one of the second plurality of optical waveguides.

Abstract: An optical multiple-input-multiple-output (MIMO) receiver includes an input port configured to receive input light; a Stokes measurement apparatus configured to generate measurements of Stokes parameters; an optical MIMO demultiplexer configured to generate a plurality of demultiplexed output light signals based on (i) the input light and (ii) the measurements of the Stokes parameters generated by the Stokes measurement apparatus; and a plurality of output ports configured to output the plurality of demultiplexed output light signals generated by the optical MIMO demultiplexer. In particular, the Stokes measurement apparatus is connected to the optical MIMO demultiplexer in a parallel arrangement.