In an EADFB laser with an integrated SOA, a new configuration in which deterioration of optical waveform quality is solved or mitigated while taking advantage of characteristics that the same layer structure can be used and the manufacturing process can be simplified is shown. In an optical transmitter of the present disclosure, a carrier density is optimized depending on a light intensity inside the SOA and an amount of carrier consumption. The SOA is electrically separated into a plurality of regions, and a current is injected into each region independently. The divided SOA region is configured so that a length of the SOA region becomes shorter as a region is farther from an incidence end of the SOA. Further, for the divided SOA, an amount of carrier consumption increases as the SOA region is farther from the incidence end, so that a current injection amount is increased.

The invention relates to the field of photonic integrated circuits and provides an optical modulator and a photonic integrated system, which can suppress phase deviation caused by carrier diffusion. The optical modulator includes at least one phase shifter including a waveguide channel for transmitting optical signal, and a P-type doped region and a N-type doped region located on opposite sides of the waveguide channel. In the waveguide channel, an undoped intrinsic region is located between the P-type doped region and the N-type doped region. At least one end of the intrinsic region or close to the at least one end is provided with a blocking structure for blocking the diffusion of carriers from the intrinsic region along the waveguide propagation direction, so that the phase deviation caused by the diffusion of carriers can be suppressed, and the electrical crosstalk between adjacent phase shifters can be suppressed, thereby avoiding modulation signal distortion caused by the electrical crosstalk. As a result, the reliability and precision of the photonic integrated system can be improved.

A method for on-silicon integration of a III-V-based material component includes providing a first substrate having a silicon-based optical layer including a waveguide, transferring a second substrate of III-V-based material on the optical layer, and forming the III-V component from the second substrate, so as to enable a coupling between the waveguide and the III-V component, by preserving a III-V-based material layer extending laterally. The method also includes forming by epitaxy from the III-V layer, an InP:Fe-based structure laterally bordering the III-V component, forming a layer including contacts configured to contact the III-V component, and transferring a third silicon-based substrate onto the layer including the contacts.

A photonic chip. In some embodiments, the photonic chip includes a waveguide; and an optically active device comprising a portion of the waveguide. The waveguide may have a first end at a first edge of the photonic chip; and a second end, and the waveguide may have, everywhere between the first end and the second end, a rate of change of curvature having a magnitude not exceeding 2,000/mm.sup.2.

A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.

Various Reservoir Computing systems and a method performed by a Reservoir Computing system are provided. A Reservoir Computing system includes a laser for emitting light. The Reservoir Computing system further includes a mirror for reflecting external feedback light back to the laser. The Reservoir Computing system also includes a modulator for modulating the external feedback light reflected back to the laser. The Reservoir Computing system additionally includes a photo-detector for converting a laser output signal to an electrical signal. The Reservoir Computing system further includes an analog-to-digital converter for sampling the electrical signal. The Reservoir Computing system also includes a controller for applying a learning algorithm to the sampled electrical signal.

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.

An electroabsorption modulator incorporates waveguiding regions along the length of the modulator that include quantum wells where at least two of the regions have quantum wells with different bandgaps. In one embodiment of the invention, the regions are arranged such that the quantum wells have bandgaps with decreasing bandgap energy along the length of the modulator from the modulator's input to its output. The bandgap energy of the quantum wells may be decreased in discrete steps or continuously. Advantageously, such an arrangement better distributes the optical absorption as well as the carrier density along the length of the modulator. Further advantageously, the modulator may handle increased optical power as compared with prior art modulators of similar dimensions, which allows for improved link gain when the optical modulator is used in an analog optical communication link.

Photonic devices having Al.sub.1-xSc.sub.xN and Al.sub.yGa.sub.1-yN materials, where Al is Aluminum, Sc is Scandium, Ga is Gallium, and N is Nitrogen and where 0<x≤0.45 and 0≤y≤1.

A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.