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: 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 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: 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: 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 A 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 µm 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 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 method, comprising modulating digital data onto an optical carrier. Modulating includes intensity splitting the optical carrier in an input optical coupler of an interferometer. The interferometer including two or more controllable optical waveguides located on a substrate, each controllable optical waveguide connecting the input optical coupler to an output optical coupler of the interferometer and having a two-state modulator along a segment thereof. Modulating include optically modulating separate data streams onto each of the optical carriers produced by the splitting. The two or more controllable optical waveguides are connected to transmit an output to the output optical coupler, substantially different light amplitudes and/or phases when the two-state modulators of the two or more controllable optical waveguides are in different states, as driven by the data streams having different information content.

Abstract: Undirected cross connects are provided based on wavelength-selective switches. An undirected Cantor network is disclosed where the switch nodes are wavelength selective switches. An undirected Clos cross connect is also disclosed where one or more undirected switches are undirected Cantor networks having at least one wavelength selective switch.