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.

The present invention relates to a semiconductor optical amplifier, the semiconductor optical amplifier including: a plurality of optical amplification regions arranged in series; a passive waveguide region provided between optical amplification regions; and first and second electrodes provided on an upper surface of each of the optical amplification regions. The passive waveguide region electrically insulates between the first electrodes and between the second electrodes of the adjacent optical amplification regions and optically connects the adjacent optical amplification regions. The semiconductor optical amplifier electrically connects the first electrode and the second electrode of the respective adjacent optical amplification regions so that the plurality of optical amplification regions are electrically connected in cascade, and feeds power to the optical amplification regions at both ends of arrangements of the plurality of optical amplification regions thereby driving the plurality of optical amplification regions.

A demultiplexer-free wavelength division multiplexing receiver based on cascaded-bandgap waveguide photodiodes, includes a substrate; and a plurality of different absorbing material sections forming a plurality of independent photodetector sections, each with a different thickness and a different bandgap. The plurality of photodetector sections may be fabricated at the same time on the same substrate, whereby different widths between each pair of mask stripes results in a different thickness of each photodetector section and a different bandgap of each photodetector section. The photodetector sections are then optically connected together into concatenated photodetector sections forming a single elongated optical waveguide.

A network system comprises a plurality of nodes and a plurality of optical amplifiers. A first node comprises a first transmitter configured to send a wavelength-division-multiplexed optical signal and a first receiver configured to receive a wavelength-division-multiplexed optical signal, and the second node comprises a second transmitter configured to send a wavelength-division-multiplexed optical signal and a second receiver configured to receive a wavelength-division-multiplexed optical signal. The first and second transmitters are optically connected to an input of the first optical amplifier and an input of the second optical amplifier, respectively, and the first and second receivers are optically connected to an output of the first optical amplifier and an output of the second optical amplifier, respectively. The receivers each comprise a photoreceiver and a reception circuit. The photoreceiver is electrically connected, by flip chip connection, to a reception circuit. A reception circuit is configured not to comprise a transimpedance amplifier.

A variable wavelength light source and an apparatus including the same are disclosed. The variable wavelength light source includes: a first waveguide; a second waveguide spaced apart from the first waveguide; a first optical amplifier including a first gain medium; and a second optical amplifier including a second gain medium that is different from the first gain medium.

In one embodiment, an electro-optical modulator includes a waveguide having a first major surface and a second major surface opposite the first major surface. A cavity is disposed in the waveguide. Multiple quantum wells are disposed in the cavity.

In an embodiment, a phase shifter includes: a light input end; a light output end; a p-type semiconductor material, and an n-type semiconductor material contacting the p-type semiconductor material along a boundary area, wherein the boundary area is greater than a length from the light input end to the light output end multiplied by a core width of the phase shifter.

A photonic transmitter is provided, including a laser source including a first waveguide made of silicon and a second waveguide made of III-V gain material, the waveguides being separated from each other by a first segment of a dielectric layer; and a phase modulator including a first electrode made of single-crystal silicon and a second electrode made of III-V crystalline material, separated from each other by a second segment of the dielectric layer, where a thickness of the dielectric layer is between 40 nm and 1 m, where a thickness of a dielectric material in an interior of the first segment is equal to the thickness of the dielectric layer, and where a thickness of the dielectric material in an interior of the second segment is between 5 nm and 35 nm, a rest being formed by a thickness of semiconductor material.

An optical modulator having a small-sized circuit and a smaller voltage drop in a terminating resistor is provided. The optical modulator includes first and second optical waveguides, a first electrode inputting a first high frequency signal into the first optical waveguide, a second electrode inputting a second high frequency signal having a reverse phase relative to the first high frequency signal into the second optical waveguide, a first terminating resistor connected to the first electrode, a second terminating resistor connected to the second electrode, a connection point connecting the first and second electrodes via the first and second terminating resistors, and a DC voltage supply connected to the connection point. A resistance value of the first terminating resistor is equal to a characteristic impedance of the first electrode. A resistance value of the second terminating resistor is equal to a characteristic impedance of the second electrode.

A method includes receiving input light having an input wavelength in a first optical resonator for causing resonance of the input light in the first optical resonator. The first optical resonator includes a non-linear optical medium. The method also includes converting at least a portion of the input light to a combination of first output light having a first output wavelength that is different from the input wavelength and second output light having a second output wavelength that is different from the input wavelength and the first output wavelength by passing the input light through the non-linear optical medium. The method further includes causing resonance of the first output light and the second output light in a second optical resonator. A portion of the first optical resonator is coupled to a portion of the second optical resonator.