Narrow-optical linewidth laser generation devices and methods for generating a narrow-optical linewidth laser beam are provided. One narrow-optical linewidth laser generation devie includes a single-wavelength mirror or multiwavelength mirror (for comb lasers) formed from one or more optical ring resonators coupled with an optical splitter. The optical splitter may in turn be coupled with a quantum dot optical amplifier (QDOA), itself coupled with a phase-tuner. The phase tuner may be further coupled with a broadband mirror. The narrow-optical linewidth laser beam is generated by using a long laser cavity and additionally by using an integrated optical feedback.

Embodiments herein relate to an apparatus for use in a hybrid laser. The apparatus may include a silicon substrate and a waveguide to facilitate transmission of an optical signal in a first direction that is orthogonal to a surface of the silicon substrate. The apparatus may further include a metal shunt that is less than or equal to 10 micrometers from the waveguide in a second direction that is orthogonal to the surface of the silicon substrate and orthogonal to the first direction. Other embodiments may be described and/or claimed.

A semiconductor optical device includes an SOI substrate having a waveguide of silicon, and at least one gain region of a group III-V compound semiconductor having an optical gain bonded to the SOI substrate. The waveguide has a bent portion and multiple linear portions extending linearly and connected to each other through the bent portion. The gain region is disposed on each of the multiple linear portions.

A device, such as a light-emitting device, e.g. a laser device, comprising: a plurality of group III-V semiconductor NWs grown on one side of a graphitic substrate, preferably through the holes of an optional hole-patterned mask on said graphitic substrate; a first distributed Bragg reflector or metal mirror positioned substantially parallel to said graphitic substrate and positioned on the opposite side of said graphitic substrate to said NWs; optionally a second distributed Bragg reflector or metal mirror in contact with the top of at least a portion of said NWs; and wherein said NWs comprise aim-type doped region and a p-type doped region and optionally an intrinsic region there between.

A method for tuning the frequency of THz radiation is provided. The method utilizes an apparatus comprising a spin injector, a tunnel junction coupled to the spin injector, and a ferromagnetic material coupled to the tunnel junction. The ferromagnetic material comprises a Magnon Gain Medium (MGM). The method comprises the step of applying a bias voltage to shift a Fermi level of the spin injector with respect to the Fermi level of the ferromagnetic material to initiate generation of non-equilibrium magnons by injecting minority electrons into the Magnon Gain Medium. The method further comprises the step of tuning a frequency of the generated THz radiation by changing the value of the bias voltage.

A semiconductor device having a GeSiSn base region combined with an emitter region and a collector region can be used to fabricate a bipolar transistor or a heterojunction bipolar transistor. The GeSiSn base region can be compositionally graded or latticed matched or strained to GaAs. The GeSiSn base region can be wafer bonded to a GaN or SiC collector region.

The invention relates to a method for fabricating a semiconductor structure. The method comprises fabricating a photonic crystal structure of a first material, in particular a first semiconductor material and selectively removing the first material within a predefined part of the photonic crystal structure. The method further comprises replacing the first material within the predefined part of the photonic crystal structure with one or more second materials by selective epitaxy. The one or more second materials may be in particular semiconductor materials. The invention further relates to devices obtainable by such a method.

Provided is an optical modulating device including a substrate including first and second trenches, a phase modulator in a region of the substrate, the phase modulator including an undoped region provided between the first and the second trenches, and first and a second doped regions which are apart from each other with the undoped region therebetween, wherein the phase modulator is configured to modulate a phase of light traveling through the undoped region based on a first electrical signal applied to the phase modulator, an amplifier including a first doped layer, a quantum well layer, a clad layer, and a second doped layer sequentially on the substrate, the amplifier overlapping at least a portion of the phase modulator and being configured to amplify the light based on a second electrical signal applied to the amplifier, and an insulating layer between the phase modulator and the amplifier.

A reflecting mirror includes a first film and a second film on the first film, and has a reflection band where a center wavelength is λ. The first film includes a layer having a first average refractive index and another layer having a second average refractive index higher than the first average refractive index. The second film includes a layer having a third average refractive index and another layer having a fourth average refractive index higher than the third average refractive index. A sum of optical film thicknesses of the two layers of the first film is λ/2. A sum of optical film thicknesses of the two layers of the second film is greater than or equal to (n+1)λ/2 (n is an integer greater than or equal to 1).

A multi-emitter laser diode device includes a carrier chip singulated from a carrier wafer. The carrier chip has a length and a width, and the width defines a first pitch. The device also includes a plurality of epitaxial mesa dice regions transferred to the carrier chip from a substrate and attached to the carrier chip at a bond region. Each of the epitaxial mesa dice regions is arranged on the carrier chip in a substantially parallel configuration and positioned at a second pitch defining the distance between adjacent epitaxial mesa dice regions. Each of the plurality of epitaxial mesa dice regions includes epitaxial material, which includes an n-type cladding region, an active region having at least one active layer region, and a p-type cladding region. The device also includes one or more laser diode stripe regions, each of which has a pair of facets forming a cavity region.