Provided is a nitride semiconductor laser element which includes: a stacked structure including a plurality of semiconductor layers including a light emitting layer, the stacked structure including a pair of resonator end faces located on opposite ends; and a protective film including a dielectric body and disposed on at least one of the pair of resonator end faces. The protective film includes a first protective film (a first emission surface protective film), a second protective film (a second emission surface protective film), and a third protective film (a third emission surface protective film) disposed in stated order above the stacked structure. The first protective film is amorphous, the second protective film is crystalline, and the third protective film is amorphous.

Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuitry for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations.

A first calculation unit calculates an acceleration factor of lifetime consumption of the light source with as case of a standard temperature and standard drive condition as a reference, a second calculation unit calculates a whole lifetime or remaining lifetime of individual light sources relative to a performance index of the individual light sources or a change rate of the performance index, a computation unit obtains an effective cumulative driving time at which the magnitude of influence imparted on the lifetime is equivalent with a case of driving at the standard temperature and standard drive condition, by calculating a time integral of the acceleration factor, and a recording unit records the effective cumulative driving time and the whole lifetime or remaining lifetime together with an optical output characteristic of the light source.

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.

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.

A thermoelectric module includes a substrate; a thermoelectric element; a bonding portion including an electrode that bonds the substrate and the thermoelectric element; an organic material film that covers a front surface of the bonding portion; and an inorganic material film that covers the organic material film.

A light emitting device includes: a base having a first stepped portion and a second stepped portion; a light emitting element; an electronic member configured to be irradiated by light emitted from the light emitting element; a first wiring region located on the first stepped portion; a second wiring region located on the second stepped portion; wires connected to the light emitting element and the electronic member. The wires includes a first and second wires. The first wire has a first end that is connected to the first wiring region, and a second end. The second wire has a first end that is connected to the second wiring region, and a second end. A position of the second end of the first wire relative to the bottom face is lower than a position of the second end of the second wire relative to the bottom face.

Systems and methods for a tunable RF synthesizer based on offset optical frequency combs is provided herein. An exemplary system includes two lasers, a first laser generating a first laser output and a second laser generating a second laser output; and a coupler that receives the first and second laser outputs. Further, the system includes a resonator having first and second sections coupled to one another, the coupler coupling the first and second laser outputs into the resonator; a splitter that couples the first section to the second section, the splitter splitting a first proportion of the first laser output and a second proportion of the second laser output onto different paths within the resonator; and a controller that controls the splitter to change a size of the first proportion in relation to the first laser and the second proportion in relation to the second laser.

Systems and methods for a tunable RF synthesizer based on offset optical frequency combs is provided herein. An exemplary system includes two lasers, a first laser generating a first laser output and a second laser generating a second laser output; and a coupler that receives the first and second laser outputs. Further, the system includes a resonator having first and second sections coupled to one another, the coupler coupling the first and second laser outputs into the resonator; a splitter that couples the first section to the second section, the splitter splitting a first proportion of the first laser output and a second proportion of the second laser output onto different paths within the resonator; and a controller that controls the splitter to change a size of the first proportion in relation to the first laser and the second proportion in relation to the second laser.

An optical device is provided that includes an active waveguide having a top electrode and a plurality of layers including a gain layer. Configurations are disclosed for the active waveguide to enable amplification of a guided optical wave profile while preserving a shape of a lateral optical intensity profile of the guided optical wave as the guided optical wave is amplified along the waveguide. The top electrode and/or one or more layers of the active optical waveguide may be tailored to provide a tailored optical gain.