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.

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 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.

A tunable laser for a transceiver includes a silicon photonics substrate, first and second patterned regions each being defined in the substrate a step lower than a flat surface region of the substrate, first and second laser diode chips arranged in the first and second patterned regions, the patterned regions being configured to align the gain regions of the first and second laser diode chips with integrated couplers formed in the substrate adjacent to the first and second patterned regions to facilitate flip-bonding the first and second laser diode chips within the patterned regions, and a tuning filter coupled to the first laser diode chip and the second laser diode chip via the integrated couplers. The tuning filter is configured to receive laser light from each of the first and second laser diode chips and generate a laser output having a gain determined by each of the gain regions.

A criterion method of GCCS (Globally Complete Chaos Synchronization) for three-node VCSEL (Vertical Cavity Surface Emitting Laser) networks with delay coupling is provided, including steps of: providing a delay-coupled VCSEL network consisting of three identical units and dynamic equations of the VCSEL network; providing assumptions of an outer-coupling matrix and a unitary matrix under the dynamic equations of the VCSEL network; in the three-node VCSEL network, determining rate equations of i-VCSEL, determining dynamic equations of a synchronization manifold, and determining a master-stability equation; calculating three maximum Lyapunov exponents; determining a stability of a synchronization state of the three-node VCSEL network, and determining whether the synchronization manifold of the VCSEL network is a chaotic waveform. Through a master-stability function, the method for determining whether the GCCS is achieved among all node lasers is provided, which solves a difficult problem of GCCS criterion for the VCSEL networks.

An optical path test system includes a return light test unit for emitting laser light to an optical path monitoring unit to simulate return light received by the optical path monitoring unit in a normal operation; a light path monitoring unit arranged on a light path of the return light testing unit for receiving the return light and normally emitting laser light; and a power detector for receiving the laser light emitted by the light path monitoring unit so as to monitor stability of output power of the chip when the light path monitoring unit receives the return light emitted by the return light testing unit. The technical solution in the present invention emits laser light to a tested laser chip to simulate return light received by the tested laser chip in a normal operation, and a return light resistance threshold of the laser chip can be accurately evaluated.

Example embodiments disclose a tunable optical pair source (TOPS) configured to generate first and second output optical beams having respective first and second frequencies that are phase locked with each other. The TOPS may include a first laser, such as a tunable laser, configured to generate a first laser beam, a radio frequency (RF) oscillator configured to transmit an RF reference signal, a beam splitter in optical communication with the first laser, and an electro-optic modulator configured to modulate the second split beam with the RF reference signal to form a modulated beam having a first sideband comb comprising a plurality of harmonics. Additionally, the TOPS may include an optical filter configured to receive the modulated beam and output a filtered optical beam, and a second laser configured to generate a second laser beam at the second frequency, the second laser being configured to receive the filtered optical beam as a seed.

A dual optical frequency comb light-emitting device includes a first optical-frequency-comb laser source that includes a first laser resonator having a first optical path length, a second optical-frequency-comb laser source that includes a second laser resonator having a second optical path length different from the first optical path length, and an optical coupler that causes a first portion of first optical-frequency-comb laser light emitted from the first laser resonator to enter the second laser resonator. The first optical-frequency-comb laser source outputs a second portion of the first optical-frequency-comb laser light to an outside. The second optical-frequency-comb laser source outputs second optical-frequency-comb laser light emitted from the second laser resonator to the outside.

An InP-based monolithic integrated chaotic semiconductor laser chip capable of feeding back randomly diffused light, being composed of six regions: a left DFB semiconductor laser, a bidirectional SOA, a left passive optical waveguide region, a doped passive optical waveguide region, a right passive optical waveguide region, and a right DFB semiconductor laser, specifically including: an N+ electrode layer, an N-type substrate, an InGaAsP lower confinement layer, an undoped InGaAsP multiple quantum well active region layer, doped particles, distributed feedback Bragg gratings, an InGaAsP upper confinement layer, a P-type heavily doped InP cover layer, a P-type heavily doped InGaAs contact layer, a P+ electrode layer, a light-emitting region, and isolation grooves. It effectively solves problems of bulky volume of the existing chaotic laser source, the time-delay signature of chaotic laser, narrow bandwidth, and low coupling efficiency of the light and the optical waveguide.

A laser device is provided which comprises a common waveguide layer and a plurality of laser bodies, wherein each of the laser bodies has an active region configured for generating coherent electromagnetic radiation. The laser bodies are arranged side by side on the common waveguide layer, wherein the laser bodies are directly adjacent to the common waveguide layer. In particular, the laser bodies are configured to be phase-coupled to each other via the waveguide layer during operation of the laser device.

Furthermore, a method for producing such a phase-coupled laser device is provided.