Abstract:
A high-order-mode (HOM) filter for thick silicon waveguides has a shoulder slab, a waveguide ridge, a first filter ridge, and a second filter ridge. The first filter ridge and the second filter ridge help attenuate higher-order modes from the waveguide ridge while the waveguide ridge guides a fundamental mode.
Abstract:
A widely tunable laser system includes a substrate, first and second lasers, an output and at least one optical combining device. The first laser is integrated with the substrate, includes a gain medium that includes a first material, and emits light at a wavelength that is tunable within a first wavelength range that is determined at least in part by the first material. The second laser is integrated with the substrate, includes a gain medium that includes a second material, and emits light at a wavelength that is tunable within a second wavelength range that is different from the first wavelength range that is determined at least in part by the second material. The at least one optical combining device is configured to direct light from one or both of the first laser and the second laser to the output.
Abstract:
A waveguide mode expander couples a smaller optical mode in a semiconductor waveguide to a larger optical mode in an optical fiber. The waveguide mode expander comprises a shoulder made of crystalline silicon and a ridge made of non-crystalline silicon (e.g., amorphous silicon). In some embodiments, the ridge of the waveguide mode expander has a plurality of stages, the plurality of stages have different widths and/or thicknesses at a given cross section.
Abstract:
A polarization-independent, optical circulator is formed in silicon photonics. The polarization-independent, optical circulator uses an optical splitter having two couplers and two waveguides joining the two couplers. One of the two waveguides is thinner than the other to create a large effective index difference between TE and TM modes transmitted through the one waveguide. Polarization rotators, including reciprocal and/or non-reciprocal rotators, are further used to create the optical circulator.
Abstract:
A polarization-independent, optical circulator is formed in silicon photonics. The polarization-independent, optical circulator uses an optical splitter having two couplers and two waveguides joining the two couplers. One of the two waveguides is thinner than the other to create a large effective index difference between TE and TM modes transmitted through the one waveguide. Polarization rotators, including reciprocal and/or non-reciprocal rotators, are further used to create the optical circulator.
Abstract:
An optical receiver, used in wavelength-division multiplexing, has multiple photodetectors per channel. The optical receiver comprises a demultiplexer to separate incoming light into different output waveguides, one output waveguide for each channel. A splitter is used in each output waveguide to split each output waveguide into two or more branches. A separate photodetector is coupled with each branch so that two or more photodetectors are used to measure each channel.
Abstract:
A modulator and a capacitor are integrated on a semiconductor substrate for modulating a laser beam. Integrating the capacitor on the substrate reduces parasitic inductance for high-speed optical communication.
Abstract:
A 400 Gb/s transmitter is integrated on a silicon substrate. The transmitter uses four gain chips, sixteen lasers, four modulators to modulate the sixteen lasers at 25 Gb/s, and four multiplexers to produce four optical outputs. Each optical output can transmit at 100 Gb/s to produce a 400 Gb/s transmitter. Other variations are also described.
Abstract:
An optical, directional coupler has a first input, a second input, a first output, and a second output. The coupler is made with a shoulder disposed on a substrate and a first ridge and a second ridge disposed on the shoulder. The first ridge extends from the first input to the first output. The second ridge extends from the second input to the second output. The shoulder, the first ridge, and the second ridge taper to provide coupling and are modified to select a coupling ratio. Further, a tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The directional coupler provides an output coupler for the tunable laser.
Abstract:
A waveguide coupler has a compression region and an expansion region for coupling light between a silicon waveguide and an optical fiber. The compression region receives light from the silicon waveguide and compresses an optical mode of the light. Light is transmitted from the compression region to an expansion region. The expansion region expands the light to have a larger cross section. Light is then transmitted to the optical fiber.