A broad area quantum cascade laser includes an optical cavity disposed between two sidewalls, the optical cavity including an active region for producing photons when a current is applied thereto, where the optical cavity is subject to a presence of at least one high order transverse optical mode due to its broad area geometry. The broad area quantum cascade laser may also include an optically lossy material disposed on at least a first portion of one or more of the two sidewalls.

A system includes a grating coupled laser and a photonic integrated circuit (PIC). The grating coupled laser includes a first waveguide and a transmit grating coupler optically coupled to the first waveguide. The PIC includes a second waveguide and a receive grating coupler optically coupled to the second waveguide. The receive grating coupler is in optical alignment with the transmit grating coupler. The receive grating coupler includes a first grating and a second grating spaced apart from and above the first grating within the PIC.

Disclosed herein is a laser structure comprising an active region overlying a GaAs substrate. The active region includes a dilute nitride material. The laser is configured to generate light at wavelengths greater than 1300 nm. Also disclosed herein is a photodetector comprising an absorber layer overlying a GaAs substrate. The absorber layer includes a dilute nitride material. The photodetector is configured to detect light at wavelengths greater than 1300 nm. Exemplary dilute nitride materials may include, but are not limited to, GaInNAs and GaInNAsSb. Embodiments of the disclosure may include a dilute nitride-on-GaAs laser structure and a dilute nitride-on-GaAs photodetector.

Methods for designing a mode-selective optical device including one or more optical interfaces defining an optical cavity include: defining a loss function within a simulation space encompassing the optical device, the loss function corresponding to an electromagnetic field having an operative wavelength within the optical device resulting from an interaction between an input electromagnetic field at the operative wavelength and the one or more optical interfaces of the optical device; defining an initial structure for each of the one or more optical interfaces, each initial structure being defined using a plurality of voxels; determining values for at least one structural parameter and/or at least one functional parameter of the one or more optical interfaces by solving Maxwell's equations; and defining a final structure of the one or more optical interfaces based on the values for the one or more structural and/or functional parameters.

A photonic circuit with a hybrid III-V on silicon or silicon-germanium active section, that comprises an amplifying medium with a III-V heterostructure (1, QW, 2) and an optical wave guide. The wave guide comprises a coupling section (31) facing a central portion of the amplifying medium, a propagation section (34, 35) and a modal transition section (32, 33) arranged between the coupling section and the propagation section. In the modal transition section, the optical wave guide widens progressively from the propagation section towards the coupling section.

A semiconductor optical amplifier is configured to provide output light with reduced optical chirp when pulsed. The semiconductor optical amplifier includes a waveguide and a diffraction grating positioned between a first semiconductor layer and a second semiconductor layer. The semiconductor optical amplifier emits output light through a two-dimensional surface of the first semiconductor layer or the second semiconductor layer. The diffraction grating may be a 1D or 2D photonic crystalline structure that directs light to the waveguide to facilitate amplification through constructive interference. The semiconductor optical amplifier is configured to support narrow line widths and single mode laser operations.

Some embodiments relate to a vertical cavity surface emitting laser (VCSEL) device including a VCSEL structure overlying a substrate. The VCSEL structure includes a first reflector, a second reflector, and an optically active region disposed between the first and second reflectors. A first spacer laterally encloses the second reflector. The first spacer comprises a first plurality of protrusions disposed along a sidewall of the second reflector.

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.

The embodiment relates to a light-emitting device in which a positional relationship between a modified refractive index region's gravity-center position and the associated lattice point differs from a conventional device, and a production method. In this device, a stacked body including a light-emitting portion and a phase modulation layer optically coupled to the light-emitting portion is on a substrate. The phase modulation layer includes a base layer and plural modified refractive index regions in the base layer. Each modified refractive index region's gravity-center position locates on a virtual straight line passing through a corresponding reference lattice point among lattice points of a virtual square lattice on the base layer's design plane. A distance between the reference lattice point and the modified refractive index region's gravity center along the virtual straight line is individually set such that this device outputs light forming an optical image.

Some embodiments relate to a method for manufacturing a vertical cavity surface emitting laser. The method includes forming an optically active layer over a first reflective layer and forming a second reflective layer over the optically active layer. Forming a masking layer over the second reflective layer, where the masking layer leaves a sacrificial portion of the second reflective layer exposed. A first etch is performed to remove the sacrificial portion of the second reflective layer, defining a second reflector. Forming a first spacer covering outer sidewalls of the second reflector and masking layer. Performing an oxidation process to oxidize a peripheral region of the optically active layer. A second etch is performed to remove a portion of the oxidized peripheral region, defining an optically active region. Forming a second spacer covering outer sidewalls of the first spacer, the optically active region, and the first reflector.