Photonic devices having a quantum well structure that includes a Group III-N material, and a Al.sub.1-xSc.sub.xN cladding layer disposed on the quantum well structure, where 0<x≤0.45, the Al.sub.1-xSc.sub.xN cladding layer having a lower refractive index than the index of refraction of the quantum well structure.

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 tunable laser that is characterized by including a gain waveguide ACT made of an optically active semiconductor material, and a tunable wavelength filter TWF that selects light of a specific wavelength using current injection, which are integrated on a compound semiconductor substrate S, in which at least one or more of the tunable wavelength filters TWF are formed to select a specific wavelength of light from the light from the waveguide ACT and return the selected specific wavelength of light back to the waveguide ACT, and a semiconductor mixed crystal material constituting the tunable wavelength filter TWF has a strained multiple quantum well structure MQW in which a mixed crystal material ratio changes periodically.

A tunable laser that is characterized by including a gain waveguide ACT made of an optically active semiconductor material, and a tunable wavelength filter TWF that selects light of a specific wavelength using current injection, which are integrated on a compound semiconductor substrate S, in which at least one or more of the tunable wavelength filters TWF are formed to select a specific wavelength of light from the light from the waveguide ACT and return the selected specific wavelength of light back to the waveguide ACT, and a semiconductor mixed crystal material constituting the tunable wavelength filter TWF has a strained multiple quantum well structure MQW in which a mixed crystal material ratio changes periodically.

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 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 Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

A radiative heatsink includes a cold plate, a radiator mounted to the cold plate and a thermal compound located between and coupling the heat source to the cold plate. The thermal compound converts a portion of a first phononic thermal energy from the heat source into a first photonic near-field and a first photonic far-field thermal radiation and transfers the first photonic near-field, the first photonic far-field and the remaining of the first phononic thermal energy to the cold plate. The cold plate combines the first photonic near-field, the first photonic far-field and the remaining first phononic thermal energy into a second phononic thermal energy and provides the second phononic thermal energy to the radiator. The radiator converts the second phononic thermal energy into a second photonic near-field and a second photonic far-field and emits the second photonic near-field or the second photonic far-field such that cold plate is regenerated.