A semiconductor device includes an electrode which is arranged on an organic material with an insulation film interposed therebetween and which does not easily peel away from the organic material along with the insulation film. An insulation film in a region including pad portions of a phase shift electrode and a modulation electrode has openings at the centers of the pad portions of the phase shift electrode and the modulation electrode, the edge portions of which are formed on the phase shift electrode and the modulation electrode. In this way, the adjoining edges of the phase shift electrode and modulation electrode and the insulation film are all covered by the insulation film so as not to be exposed to the atmosphere. By covering the cracks that occur in the insulation film in the production process with the insulation film made of SiO.sub.2, SiN.sub.X, SiON.sub.X or the like, an organic solvent such as acetone or ethanol used in the process can be prevented from seeping in between the insulation film and the organic material through the cracks in the insulation film.

Photonic devices having a quantum well structure that includes a Group III-N material, and a Al.sub.1-xSc.sub.xN cladding layer disposed on the quantum well structure, where 0<x≤0.45, the Al.sub.1-xSc.sub.xN cladding layer having a lower refractive index than the index of refraction of the quantum well structure.

An optical semiconductor device includes an active layer having a plurality of quantum dot layers. The plurality of quantum dot layers include: a first quantum dot layer doped with a p-type impurity; and a second quantum dot layer doped with an n-type impurity and having an emission wavelength different from that of the first quantum dot layer.

A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

High bandwidth (e.g., > 100 GHz) modulators and methods of fabricating such are provided. An EAM comprises a waveguide mesa comprising a continuous multi-quantum well (MQW) layer; a plurality of electrode segments disposed on the waveguide mesa; and a microstrip transmission line disposed on an insulating material layer and in electrical communication with the plurality of electrode segments via conducting bridges. The waveguide mesa comprises alternating active sections and passive sections. An electrode segment of the plurality of electrodes is disposed on a respective one of the active sections. Portions of the continuous MQW layer disposed in each of the active sections having an energy gap defining an active energy gap value. Portions of the continuous MQW layer disposed in each of the passive sections having an energy gap defining an passive energy gap value. The active energy gap value is less than the passive energy gap value.

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.

Provided is an electro-absorption modulator that includes a substrate, a mesa structure, a first conductivity type electrode, and a second conductivity type electrode. The first conductivity type electrode includes a mesa-top electrode, a pad electrode, and a lead-out wire electrode. The mesa structure has a light input end, to which light is to be input from outside, and a light output end, which is on a side of the mesa structure that is opposite of the light input end. A connection position between a center position in a short-side direction of the lead-out wire electrode and the mesa-top electrode is closer to the light output end side in a long-side direction of the mesa-top electrode. The connection position is a position that is less than 50% from the light output end side with respect to a length in the long-side direction of the mesa-top electrode.

A laminate (22) is formed on a semiconductor substrate (10). Two or more grooves (54) are formed in the laminate (22). A mesa (24) with two grooves among the two or more grooves (54) positioned on both sides is formed. An insulating resin film (30) is embedded into the two or more grooves (54). A first opening (32) is formed at the insulating resin film (30) embedded in one of the two or more grooves (54) and an electrode (46) extracted upward from a bottom surface (36) is formed. A first side surface (34) of the insulating resin film (30) is inclined in a forward tapered direction.

A reflective spatial light modulator (SLM) made of an electro-optic material in a one-sided Fabry-Perot resonator can provide phase and/or amplitude modulation with fine spatial resolution at speeds over a Gigahertz. The light is confined laterally within the electro-optic material/resonator layer stack with microlenses, index perturbations, or by patterning the layer stack into a two-dimensional (2D) array of vertically oriented micropillars. Alternatively, a photonic crystal guided mode resonator can vertically and laterally confine the resonant mode. In phase-only modulation mode, each SLM pixel can produce a π phase shift under a bias voltage below 10 V, while maintaining nearly constant reflection amplitude. This high-speed SLM can be used in a wide range of new applications, from fully tunable metasurfaces to optical computing accelerators, high-speed interconnects, true 2D phased array beam steering, beam forming, or quantum computing with cold atom arrays.

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.