The disclosure relates in some aspects to providing miniature power-efficient agile photonic generators of microwave waveforms. Illustrative examples use chip lasers integrated in close thermal proximity with one another to provide a miniature microwave arbitrary waveform generator (AWG). Due to the small size of the lasers and the close integration, common ambient fluctuations from the environment or other sources can be efficiently reduced, yielding improved spectral purity of generated radio-frequency (RF) signals. Tight physical integration also permits a small device footprint with minimal acceleration sensitivity. The lasers may be locked to cavities or other resonators to allow efficient decoupling of the frequency and amplitude modulation of the lasers to provide flexibility to the waveform generator. Exemplary devices described herein can produce frequency chirped signals for radar applications. The frequency chirp may be linear and/or nonlinear. Tuning methods are also described herein.

An injection locking laser source is provided for an optical communications system. The injection locking laser source includes a laser cavity configured to receive an externally injected low linewidth primary light source. The laser cavity includes a cavity length, a cavity facet reflectivity, and a cavity quality factor. The injection locking laser source further includes an emitting region configured to output a secondary light source injection locked to the externally injected low linewidth primary light source at a stable detuning frequency based on a photon number, a steady-state phase, and a carrier number of the primary light source injected into the cavity.

An optical device for a quantum random number generator comprising: a source of phase randomised pulses of light, the source of phase randomised pulses of light further comprising a plurality of gain-switched lasers, each gain-switched laser having an output, and each gain-switched laser being configured to emit a stream of pulses such that the phase of each pulse in the stream of pulses is randomised, and an optical pulse combiner, the optical pulse combiner being configured to receive streams of pulses from the output of each gain-switched laser, combine the streams of pulses with one another into a combined stream of pulses and direct the combined stream of pulses into at least one output of the optical pulse combiner, the at least one output of the optical pulse combiner being the output of the source of phase randomised pulses of light; wherein the source of phase randomised pulses of light is configured such that the streams of pulses of light emitted by the plurality of gain-switched lasers are temporally offset relative to one another, a phase measurement element, the phase measurement element being configured to receive the combined stream of pulses from the output of the source of phase randomised pulses of light; and an optical detector, the optical detector being optically coupled to the phase measurement element.

A semiconductor laser includes a horizontal laser element including a first semiconductor layer arrangement having a first active zone for generating radiation. The horizontal laser element furthermore includes a first optical resonator extending in a direction parallel to a first main surface of the first semiconductor layer arrangement. Lateral boundaries of the first semiconductor layer arrangement run obliquely, such that electromagnetic radiation generated is reflectable in a direction of the first main surface of the first semiconductor layer arrangement. The semiconductor laser furthermore includes a vertical laser element having a second optical resonator extending in a direction perpendicular to the first main surface of the first semiconductor layer arrangement. The vertical laser element is arranged above the first semiconductor layer arrangement on the side of the first main surface in a beam path of electromagnetic radiation reflected at one of the lateral boundaries of the first semiconductor layer arrangement (112).

The invention relates to a laser light source (10), comprising an arrangement (120) of surface-emitting semiconductor lasers (1251, 1252, . . . 125n) to which a voltage is applied such that an operating current is below the threshold current and an intrinsic emission of the surface-emitting semiconductor laser is prevented. The laser light source also comprises a first semiconductor laser (100) which emits radiation (110) that enters the surface-emitting semiconductor laser such that induced emission takes place via the injection locking mechanism and the individual surface-emitting semiconductor lasers emit laser light having the same wavelength and polarisation direction as the irradiated radiation (110). The emission frequency of the first semiconductor laser can be changed by changing the operating current.

A semiconductor light emitter includes a substrate, a semiconductor multilayer structure including a light emission unit that emits light in an oblique direction with respect to the substrate, a base on which the substrate is disposed, a holding member that holds the substrate at an angle set in advance with respect to the base, a temperature control unit disposed parallel to the substrate to adjust a temperature of the substrate, and a shaping optical system held against the substrate to shape a luminous flux emitted from the semiconductor multilayer structure.

A semiconductor light emitter includes a substrate, a semiconductor multilayer structure including a light emission unit that emits light in an oblique direction with respect to the substrate in an emission region in a longitudinal direction and a lateral direction orthogonal to the longitudinal direction, and a shaping optical system that shapes a luminous flux emitted from the light emission unit, in which a lens closest to the light emission unit in the shaping optical system is a cylindrical lens having positive power in the lateral direction, a front major plane of the cylindrical lens is parallel to the light emission unit and a generatrix direction of the cylindrical lens is parallel to the longitudinal direction, and the following conditional equation (1) is satisfied in a case where a distance from the light emission unit to a light incident surface of the cylindrical lens is D, a distance from the light incident surface to the front major plane of the cylindrical lens is HA, and a focal length of the cylindrical lens is f,

D<f−HA  (1).

GaN-based nanowire heterostructures have been intensively studied for applications in light emitting diodes (LEDs), lasers, solar cells and solar fuel devices. Surface charge properties play a dominant role on the device performance and have been addressed within the prior art by use of a relatively thick large bandgap AlGaN shell covering the surfaces of axial InGaN nanowire LED heterostructures has been explored and shown substantial promise in reducing surface recombination leading to improved carrier injection efficiency and output power. However, these lead to increased complexity in device design, growth and fabrication processes thereby reducing yield/performance and increasing costs for devices. Accordingly, there are taught self-organising InGaN/AlGaN core-shell quaternary nanowire heterostructures wherein the In-rich core and Al-rich shell spontaneously form during the growth process.

A beam combining device and method for a Bragg grating external-cavity laser module has a plurality of side by side light-emitting modules that use a Bragg grating to perform wavelength locking. Output light of the modules is incident to a beam combining element after passing through a focusing optical element for beam combining, and light subjected to beam combining is reflected partially and transmitted partially under the effect of a light splitting element. A part is incident into a dispersion element at a diffraction angle of the element. Parallel light is formed under the effect of a conversion optical element. Spots of the light beams of corresponding wavelengths of the light-emitting modules are formed on an image acquisition mechanism. Whether the wavelengths of the corresponding light-emitting modules are locked is determined by whether there is a deviation between preset spots and spots formed by the module on the acquisition mechanism.

A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized.