An optical apparatus comprising at least two optoelectronic devices fabricated on the same substrate and in thermal communication with each other. A first optoelectronic device is configured to generate optical signals and provide them to an optical system via an optical output port. A second optoelectronic device is configured to provide heat compensation for the first optoelectronic device. An electrical circuitry provides first electrical signals to the first optoelectronic device and second electrical signals to the second optoelectronic device. The electrical circuitry is configured to adjust at least the second electrical signals to controllably adjust a temperature of the first optoelectronic device.

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.

A laser system for generating a narrow linewidth semiconductor light beam includes a substrate, a gain chip affixed on the substrate and configured to amplify light beam, and an optical feedback photonic chip affixed on the substrate, optically coupled to the gain chip, and configured to output light beam, which has a narrow linewidth around a resonant frequency of the optical feedback photonic chip, to the gain chip. The optical feedback photonic chip includes first and second optical gratings, a first multimode interferometer (MMI) and a second MMI optically coupled with a respective end of the first and second optical gratings, a third MMI configured to output two light beams to the first and second MMIs, respectively, through a respective waveguide. Based on receiving a respective one of the two light beams, the first MMI outputs two light beams to its respective end of the first and second optical gratings and the second MMI outputs two light beams to its respective end of the first and second optical gratings, the first and second optical gratings output second and third light beams, the second light beam, of which a linewidth is narrower than a linewidth of the third light beam, is directed to the third MMI, and an output port of the third MMI is configured to direct the second light beam to the gain chip.

A system comprising a laser 1001 for illuminating a sample S under investigation, a temperature sensor 1019 for sensing the operating temperature of the laser 1001 and generating an output which is indicative of the sensed temperature, a temperature stabilisation device 1018 for controlling the operating temperature of the laser 1001, and a controller 1012 for determining a target operating temperature or temperature range for the laser based on the output of the temperature sensor 1019 and for controlling the temperature stabilisation device 1018 to drive the operating temperature of the laser 1001 towards the target operating temperature or temperature range.

Integrated laser sources emitting multi-wavelengths of light with reduced thermal transients and crosstalk and methods for operating thereof are disclosed. The integrated laser sources can include one or more heaters and a temperature control system to maintain a total thermal load of the gain segment, the heater(s), or both of a given laser to be within a range based on a predetermined target value. The system can include electrical circuitry configured to distribute current to the gain segment, the heater(s), or both. The heater(s) can be located proximate to the gain segment, and the distribution of current can be based on the relative locations. In some examples, the central laser can be heated prior to being activated. In some examples, one or more of the plurality of lasers can operate in a subthreshold operation mode when the laser is not lasing to minimize thermal perturbations to proximate lasers.

This application relates to a laser assembly displaying self-heating mitigation. The laser assembly comprises a semiconductor laser and a drive unit for driving the semiconductor laser. The semiconductor laser includes a first semiconductor region for generating or modulating an optical signal in response to a first drive current that is applied to the first semiconductor region, and a heating region that is arranged in proximity to the first semiconductor region and electrically insulated from the first semiconductor region. The drive unit is configured to generate the first drive current and a second drive current, apply the first drive current to the first semiconductor region during respective transmission periods of the semiconductor laser, and apply the second drive current to the heating region in intervals between successive transmission periods.

A method of determining initial parameters and target values for tuning an emission wavelength of a wavelength tunable laser capable of emitting laser light in a substantial wavelength range is disclosed. The method iterates an evaluation of initial parameters and target values at target wavelengths in a preset order. The evaluation includes steps of supplying empirically obtained parameters to the t-LD, confirming whether the t-LD generates an optical beams, determining the initial parameters and the target values by carrying out feedback loops of the AFC and the APC when the t-LD generates the optical beam, or shifting the wavelength range so as to exclude the current target wavelength when the t-LD generates no optical beam.

An optical apparatus comprising at least two optoelectronic devices fabricated on the same substrate and in thermal communication with each other. A first optoelectronic device is configured to generate optical signals and provide them to an optical system via an optical output port. A second optoelectronic device is configured to provide heat compensation for the first optoelectronic device. An electrical circuitry provides first electrical signals to the first optoelectronic device and second electrical signals to the second optoelectronic device. The electrical circuitry is configured to adjust at least the second electrical signals to controllably adjust a temperature of the first optoelectronic device.

A laser comprising a laser cavity formed by a first optical reflector, a gain region, a second optical reflector having a plurality of reflection peaks, and at least one optically active region. The first mirror may be a DBR or comb mirror and the second mirror may be a comb mirror. The spectral reflectance of the second optical reflector is adjusted at least partially based on an electric signal received form the optically active region such that only one reflection peak is aligned with a cavity mode formed by the first and second reflector.

A transmitting unit of a LIDAR device includes at least two radiation sources for generating and emitting punctiform or linear electromagnetic beams into a scanning range, at least one of the radiation sources including an operating temperature settable as a function of an emission angle of the electromagnetic beams generated by the at least one radiation source. The different operating temperatures can generate beams having angle-dependent emission wavelengths, which can result in an improvement of the signal-to-noise ratio of a LIDAR device.