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.

A method of fabricating a semiconductor structure with multiple quantum wells, comprising: providing a substrate comprising a binary semiconductor compound having a first lattice constant; depositing: a first layer on the substrate, the first layer of a first semiconductor alloy, and a second layer in contact with the first layer, the second layer of a second semiconductor alloy, to form a first stack of substantially planar semiconductor layers on the substrate; depositing in contact with the first stack a third layer of a binary semiconductor compound having the first lattice constant; depositing at least: a fourth layer on the third layer, the fourth layer comprising a third semiconductor alloy comprising InP, and a fifth layer in contact with the fourth layer, the fifth layer comprising a fourth semiconductor alloy comprising InP, to form a second stack of substantially planar semiconductor layers on the third layer.

An optical transmission apparatus includes a first multilevel optical phase modulator and a first semiconductor optical amplifier. The first semiconductor optical amplifier includes a first active region having a first multiple quantum well structure. Assuming that a first number of layers of a plurality of first well layers is defined as n.sub.1 and a first length of the first active region is defined as L.sub.1 (μm): (a) n.sub.1=5 and 400≤L.sub.1≤563; (b) n.sub.1=6 and 336≤L.sub.1≤470; (c) n.sub.1=7 and 280≤L.sub.1≤432; (d) n.sub.1=8 and 252≤L.sub.1≤397; (e) n.sub.1=9 and 224≤L.sub.1≤351; or (f) n.sub.1=10 and 200≤L.sub.1≤297.

A method for making a semiconductor device may include forming a plurality of waveguides on a substrate, and forming a superlattice overlying the substrate and waveguides. The superlattice may include a plurality of stacked groups of layers, with each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may further include forming an active device layer on the superlattice comprising at least one active semiconductor device.

An electro-optically active device comprising: a silicon on insulator (SOI) substrate including a silicon base layer, a buried oxide (BOX) layer on top of the silicon base layer, a silicon on insulator (SOI) layer on top of the BOX layer, and a substrate cavity which extends through the SOI layer, the BOX layer and into the silicon base layer, such that a base of the substrate cavity is formed by a portion of the silicon base layer; an electro-optically active waveguide including an electro-optically active stack within the substrate cavity; and a buffer region within the substrate cavity beneath the electro-optically active waveguide, the buffer region comprising a layer of Ge and a layer of GaAs.

A method of manufacturing an optoelectronic device. The manufactured device includes a photonic component coupled to a waveguide. The method comprising: providing a device coupon, the device coupon including the photonic component; providing a silicon platform, the silicon platform comprising a cavity within which is a bonding surface for the device coupon; transfer printing the device coupon onto the cavity, such that a surface of the device coupon directly abuts the bonding surface and at least one channel is present between the device coupon and a sidewall of the cavity; and filling the at least one channel with a filling material via a spin-coating process, to form a bridge coupling the III-V semiconductor based photonic component to the silicon waveguide.

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.

An electro-optically active device comprising: a silicon on insulator (SOI) substrate including a silicon base layer, a buried oxide (BOX) layer on top of the silicon base layer, a silicon on insulator (SOI) layer on top of the BOX layer, and a substrate cavity which extends through the SOI layer, the BOX layer and into the silicon base layer, such that a base of the substrate cavity is formed by a portion of the silicon base layer; an electro-optically active waveguide including an electro-optically active stack within the substrate cavity; and a buffer region within the substrate cavity beneath the electro-optically active waveguide, the buffer region comprising a layer of Ge and a layer of GaAs.

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.

Photonic devices having a photonic waveguiding layer, and a cladding layer, disposed on the photonic waveguiding layer, and where the cladding section is a material comprising Scandium. The cladding layer may include a material comprising Al.sub.1-xSc.sub.xN material where 0<x≤0.45.