A laser structure includes a substrate and a first dielectric layer formed on the substrate. A multi-quantum well is formed on the first dielectric layer and has a plurality of alternating layers. The alternating layers include a dielectric layer having a sub-wavelength thickness and a monolayer of a two dimensional material.

According to an example of the present disclosure a semiconductor laser diode includes a layer of graphene between an active laser region and a semiconductor substrate structure. The semiconductor laser diode may further include a first pair of electrodes to apply a potential difference across the active laser region and a second pair of electrodes to apply a potential difference across the layer of graphene.

Integrated circuitry is fabricated from semiconductor layers formed on a substrate, which include at least one n-type layer, an inverted p-type modulation doped quantum well (mod-doped QW) structure, a non-inverted n-type mod-doped QW structure, and at least one p-type layer including a first P+-type layer formed below a second P-type layer. An etch operation exposes the second p-type layer. P-type ions are implanted into the exposed second p-type layer. A gate electrode of a n-channel HFET device is formed in contact with the p-type ion implanted region. Source and drain electrodes of the n-channel HFET device are formed in contact with n-type ion implanted regions formed in contact with the n-type mod-doped QW structure. P-channel HFET devices, complementary BICFET devices, stacked complementary HFET devices and circuits and/or logic gates based thereon, and a variety of optoelectronic devices and optical devices can also be formed as part of the integrated circuitry.

A tunable laser includes a semiconductor optical amplifier (SOA) having a reflective end coupled to a shared reflector and an output end, which is coupled to a demultiplexer through an input waveguide. The demultiplexer comprises a set of Mach-Zehnder (MZ) lattice filters, which function as symmetric de-interleaving wavelength splitters, that are cascaded to form a binary tree that connects an input port, which carries multiple wavelength bands, to N wavelength-specific output ports that are coupled to a set of N reflectors. A set of variable optical attenuators (VOAs) is coupled to outputs of the MZ lattice filters in the binary tree, and is controllable to selectively add loss to the outputs, so that only a single favored wavelength band, which is associated with a favored reflector in the set of N reflectors, lases at any given time. An output waveguide is optically coupled to the lasing cavity.

The invention is a passively mode-locked ultrashort pulse fiber laser for generating ultrashort laser pulses, including a resonator in a figure-of-eight configuration, wherein the resonator has a main ring and a secondary ring optically coupled thereto designed as a non-linear Sagnac interferometer, and wherein the main ring and the secondary ring are constructed of polarization-maintaining optical fibers, and the main ring and/or secondary ring have a fiber section designed as a laser-active medium, wherein the laser-active medium is optically pumped through an externally-coupled pump light source which is also comprised, wherein the ultrashort pulse fiber laser is developed in that a separate optical unit is provided in the resonator as a dispersion compensation unit for compensating a group delay dispersion of the ultrashort laser pulses.

An optical resonator device, which can be implemented in a Brillouin laser, comprises a first waveguide ring resonator having a first diameter, and one or more second waveguide ring resonators adjacent to the first waveguide ring resonator. The one or more second waveguide ring resonators each have a second diameter that is less than the first diameter. The one or more second waveguide ring resonators optically communicate with the first waveguide ring resonator, such that an optical signal in the first waveguide ring resonator optically couples into the one or more second waveguide ring resonators. The one or more second waveguide ring resonators is configured such that when the optical signal resonates within the first waveguide ring resonator and the one or more second waveguide ring resonators, the optical signal within the first waveguide ring resonator is suppressed.

The present invention provides one or more injection-lockable whistle-geometry semiconductor ring lasers, which may be cascaded, that are integrated on a common silicon-on-insulator (SOI) substrate with a single-frequency semiconductor master laser, wherein the light output from the semiconductor master laser is used to injection-lock the first of the semiconductor ring lasers. The ring lasers can be operated in strongly injection-locked mode, while at least one of them is subjected to direct injection current modulation.

A ring cavity device includes a passive ring waveguide and an input/output waveguide horizontally coupled to the passive ring waveguide, including an active waveguide structure vertically coupled to the passive ring waveguide and/or the input/output waveguide. The active waveguide structure compensates for the loss of the passive ring waveguide. A method for fabricating a ring cavity device is also included. The ring cavity device may obtain part of the gain by vertical coupling or mixed coupling (vertical coupling followed by horizontal coupling) thus to compensate the loss in the ring cavity device. Hence, the quality factor of the ring cavity device is improved.

Embodiments described herein provide a layered structure that comprises a substrate that includes a first porous multilayer of a first porosity, an active quantum well capping layer epitaxially grown over the first porous multilayer, and a second porous multilayer of the first porosity over the active quantum well capping layer, where the second porous multilayer aligns with the first porous multilayer.

A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror on the substrate, a first semiconductor layer on the first multilayer film reflecting mirror, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer on the light-emitting layer. The second semiconductor layer includes a low resistance region and a high resistance region on an upper surface. The high resistance region is depressed from the low resistance region toward the light-emitting layer outside the low resistance region and impurities of the second conductivity type are inactivated in the high resistance region such that the high resistance region has an electrical resistance higher than an electrical resistance of the low resistance region. A light-transmitting electrode layer is in contact with the low resistance region and the high resistance region, and a second multilayer film reflecting mirror is on the light-transmitting electrode layer.