Research on the external cavity wavelength-locked red light semiconductor laser with a narrow-linewidth

An external cavity wavelength-locked red semiconductor laser with a narrow-linewidth was designed and fabricated. The AlGaInP strained quantum wells were meticulously designed and grown,while the epitaxial layer of a high-power red semiconductor laser was synthesized using metal-organic chemical vapor deposition (MOCVD).The chips were fabricated by photolithography, metal electrode fabrication, cavity surface coating and other processes. The prepared laser chip with the cavity length of 1.5 mm has a strip width of 100 μm. The chip was made into a laser device through packaging technique, and an external resonant cavity was constructed using a Volume Bragg Grating. A series of oexperiments were conducted to optimize the performance of laser devices, and the characteristics of spectrum, power and other parameters in the condition of free running spectrum and wavelength-locked spectrum at different temperatures. A narrow-linewidth red semiconductor laser with the central wavelength of 640 nm, the linewidth of 0.11 nm, and the power of 2.7 W was obtained by means of the continuous drive current measurement at room temperature with the drive current of 3 A and fiber parameters of 50/125. In addition, the output power of 5.02 W was achieved with the method of the quasi-continuous drive current of 5 A.The power loss of the external cavity mode-locked using VBG is controlled within 3%.