Provided is an IQ optical modulator including a nest-type MZ optical waveguide having optical modulation regions of I channel and Q channel End portions of an input optical waveguide and an output optical waveguide of the IQ optical modulator are located on a same edge face of a chip of the IQ optical modulator, an optical cross waveguide is included in which an optical waveguide between a first optical combiner and a second optical combiner of the nest-type MZ optical waveguide and the input optical waveguide cross each other, a first optical divider is provided between the I-channel optical modulation region and the Q-channel optical modulation region, and a light propagation direction in the first optical divider and a light propagation direction in the optical modulation regions are opposite to each other.

Configurations for an interferometric device used for multiplexing and de-multiplexing light are disclosed. The interferometric device may include a first input waveguide, a second input waveguide, an interferometric waveguide, and an output waveguide. A fundamental mode of light may be launched into the first and second input waveguides, and the interferometric waveguide may receive the fundamental mode and generate a higher order mode of light, where the two modes of light may be superimposed while propagating through the interferometric waveguide. The two modes of light may be received at an output waveguide that collapses the two modes into a single mode. The light propagating through the interferometric device may be used for increasing optical power even though the wavelengths of light may be different from one another. Additionally, the interferometric device may reduce coherent noise.

A method for making a multimode interference (MMI) coupler with an arbitrary desired splitting ratio includes forming a thin-film of silicon-nitride material overlying a SOI substrate. The method further includes obtaining geometric parameters of a standard MIMI coupler including a rectangular MMI block and one input port and two output ports in taper shape with one of standard splitting ratios under self-imaging principle which is close to the desired splitting ratio. Additionally, the method includes tunning the input port to an off-center position at front edge of the MMI block. The method further includes making a first output port to a first off-center position flushing with a side edge of the MMI block, adjusting a second output port to a second off-center position. The method includes tunning the MMI block to obtain optimized geometric parameters for approaching the selected arbitrary splitting ratio, and etching the thin-film of silicon-nitride material.

A method for making a multimode interference (MMI) coupler with an arbitrary desired splitting ratio includes forming a thin-film of silicon-nitride material overlying a SOI substrate. The method further includes obtaining geometric parameters of a standard MIMI coupler including a rectangular MMI block and one input port and two output ports in taper shape with one of standard splitting ratios under self-imaging principle which is close to the desired splitting ratio. Additionally, the method includes tunning the input port to an off-center position at front edge of the MMI block. The method further includes making a first output port to a first off-center position flushing with a side edge of the MMI block, adjusting a second output port to a second off-center position. The method includes tunning the MMI block to obtain optimized geometric parameters for approaching the selected arbitrary splitting ratio, and etching the thin-film of silicon-nitride material.

A compressive/transform imager comprising a lens array positioned above input ports for collecting light into the input ports, waveguides routing the light from the input port to waveguide mixing regions (e.g. multi-mode interference couplers), and detectors for receiving outputs of the waveguide mixing regions.

An integrated optical structure for multiplexing and/or demultiplexing an optical signal comprises a main waveguide having two parallel side surfaces, a first waveguide which meets the main waveguide at a first region on one of the two side surfaces, and a plurality of second waveguides which meet the main waveguide at a second region on one of the two side surfaces. The second region is spaced at a determined distance from the first region. The two side surfaces are arranged at a first angle relative to an extension direction of the first waveguide and a second angle relative to extension directions of the plurality of second waveguides. The optical structure further comprises one or more waveguide extension structures. Each waveguide extension structure is arranged adjacent to one of the two side surfaces of the main waveguide at a region that is different to the first and the second region.

A system for integrated power combiners is disclosed and may include receiving optical signals in input optical waveguides and phase-modulating the signals to configure a phase offset between signals received at a first optical coupler, where the first optical coupler may generate output signals having substantially equal optical powers. Output signals of the first optical coupler may be phase-modulated to configure a phase offset between signals received at a second optical coupler, which may generate an output signal having an optical power of essentially zero and a second output signal having a maximized optical power. Optical signals received by the input optical waveguides may be generated utilizing a polarization-splitting grating coupler to enable polarization-insensitive combining of optical signals. Optical power may be monitored using optical detectors. The monitoring of optical power may be used to determine a desired phase offset between the signals received at the first optical coupler.

A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide.

According to the present invention, a semiconductor device includes a substrate comprising a front end face, a rear end face and side faces, a plurality of semiconductor lasers provided on the substrate, a forward optical multiplexer to multiplex forward output light of the plurality of semiconductor lasers and output the multiplexed light to the front end face, a backward optical multiplexer to multiplex backward output light of the plurality of semiconductor lasers and output the multiplexed light to the rear end face and a plurality of backward waveguides connected to an output section of the backward optical multiplexer, wherein the plurality of backward waveguides includes a main waveguide disposed at a center of the output section and a plurality of lateral waveguides disposed on both sides of the main waveguide to bend toward the side faces and output light from the side faces diagonally to the side faces.

A photonic platform based polarization controller providing a fixed target polarization is disclosed. The polarization controller has a polarization rotator splitter splitting the beam into first and second feeds corresponding to first and second orthogonal polarization components. A first Mach-Zehnder interferometer (MZI) stage provides a first phase delay between the first and second feeds based on a first control signal, and a first mixer mixes the first and second feeds to provide third and fourth feeds. A second MZI stage provides a second phase delay between the third and fourth feeds based on a second control signal, and a second mixer mixes the third and fourth feeds to provide fifth and sixth feeds. A third MZI stage provides a third phase delay between the fifth and sixth feeds based on a third control signal, and a third mixer mixes the fifth and sixth feeds to provide the fixed target polarization. An optical tap splits a portion of the beam.