Results and Discussios The performance of the laser arrays for different head sink temperatures and injected currents under quasi-continuous conditions (pulse width of 200 μs and frequency of 20 Hz) is reported. At an injection current of 150 A, the heat sink temperature increases from -10 ℃ to 60 ℃, and the drift coefficient of the laser emission wavelength with temperature is 0.06 nm/℃ (Fig. 3). At 25 ℃, the drift coefficient of laser emission wavelength with current is 0.006 nm/A at 50-150 A (Fig. 4). 808 nm DFB laser arrays exhibit suitable wavelength stabilization. Under the same injection current, the output power of the DFB laser array decreases as the temperature of the heat sink increases (Fig. 5). When the heat sink temperature exceeds 40 ℃, the DFB laser array is saturated, indicating that the characteristic temperature of the DFB laser array is low. In order to improve the stability of DFB laser at different temperatures,the morphology of the grating should be optimized it by optimizing the process conditions of the grating preparation.

8XX nm high-power semiconductor lasers have wide applications in pumping solid-state lasers. The absorption peak of doped ions in the solid state is extremely narrow, typically only a few nanometers. However, the temperature drift coefficient of a typical Fabry-Pérot laser is approximately 0.3 nm. When the operating temperature changes just a bit, the emission spectrum deviates from the absorption spectrum of the ions doped in the crystal, decreasing the pumping efficiency. Developing 808 nm semiconductor lasers with stabilized wavelengths is crucial for improving pumping efficiency. In this study, an 808-nm-distributed feedback (DFB) laser diode array is prepared, and the theoretical basis of the grating design, device structure, and fabrication process are introduced. The emission wavelength of the 808 nm array laser exhibits a drift coefficient of 0.06 nm/℃ with temperature, a locking range of 70 ℃ (-10-60 ℃), and a drift coefficient of 0.006 nm/A with the current. This study demonstrates favorable conditions for improving the temperature-locking range of array lasers.

First, the relevant parameters of the first-order grating, such as the grating period and etching depth, were determined using the coupled wave theory. Next, 808 nm laser arrays were grown via metal-organic chemical vapor deposition (MOCVD) in two steps. After the first epitaxial growth, the grating (Fig. 2) was prepared using nanoimprinting lithography and inductively coupled plasma (ICP) dry etching and wet etching processes. Subsequently, in the second epitaxial step, the p-AlGaAs grating covering layer, p-AlGaAs cladding layer, and GaAs contact layer were grown. Finally, the wafer was prepared in laser arrays using lithography, electrode preparation, coating, and packaging processes. The performances of the DFB laser arrays and the laser arrays without an inner grating with different heat sink temperatures and injection currents were measured. The results were analyzed.

A high-power DFB laser array is prepared by combining theoretical analysis and experiments. The laser has a transverse length of 1 cm and cavity length of 1 mm with 83 emitters. The fill factor reaches a maximum of 80%. The test results show that the drift coefficient of the laser emission wavelength with temperature is 0.06 nm/℃, the wavelength locking range is 70 ℃, and the drift coefficient of laser emission wavelength with current is 0.006 nm/A. When the current is 150 A and the heat sink temperature is 10 ℃, the quasi-continuous output power of the laser can reach 140 W.