Research On High Brightness Volume Bragg Grating External Cavity Red Light Semiconductor Laser

Laser display has become a new generation of display technology because of its advantages of wide color gamut,long life,energy saving and environmental protection.The red light semiconductor laser for laser display is the core light source.With the development of laser display industry,higher requirements are put forward for the red light semiconductor laser,not only requires the device itself to have good beam quality and higher brightness,but also requires the device's narrow bandwidth output.Therefore,it is of great significance to analyze and improve the beam and spectral characteristics of red light laser diode for laser display.The main research contents and results of this paper are as follows:Red light external cavity semiconductor lasers are constructed using a reflective volume bragg grating(VBG)as a feedback element,and the optical characteristics of the device's output are experimentally studied.The influence of the position of volume bragg gratings on the output characteristics of red light external cavity semiconductor lasers with different external cavity structures is mainly studied.The experimental results show that as the distance between the volume bragg grating and the red light semiconductor laser chip decreases,the mode locking quality of the laser is improved,and the beam divergence angle in the slow axis direction is improved to a certain extent;at the same time,the near field The broadening phenomenon began to increase and the beam quality decreased.When a volume bragg grating with a diffraction efficiency of 20% is used in the experiment,the output wavelength of the semiconductor laser can be stably locked near 634 nm with the FAC-SAC-VBG structure.The spectral line width is compressed to about 0.7nm and the output power can reach 1.06 W.ZEMAX optical design software was used to design and simulate the optical path of the fiber coupling structure of the red light external cavity semiconductor lasers.The design structure used three step heat sinks to combine the three red light chips and realize the coupling output in a fiber with a core diameter of 105 ?m;The steady-state thermal analysis was performed using ANSYS finite element analysis software to analyze the temperature distribution of the fiber-coupled structure of the external cavity red light semiconductor laser of the volume bragg grating.The simulation results show that the output power of the fiber-coupled structure of the volume bragg grating external cavity red light semiconductor lasers is 2.83 W,the coupling efficiency reaches 94.3%,and the package thermal resistance of the laser is about 5.7K / W.Based on the simulation results of ZEMAX,three 635 nm red light chips are used to design and package the fiber coupling structure of the high brightness volume bragg grating external cavity red light semiconductor lasers.The test results show that at 14?,the output beam of the fiber coupling structure of the volume bragg grating external cavity red light semiconductor lasers is coupled into a multimode fiber with a numerical aperture of 0.22 and a core diameter of 105?m,the output end power of the fiber reaches 2.5W,the coupling efficiency reaches 70%,the spectrum of the output light of the fiber is stably locked at about 636 nm,and the stable output of high brightness is achieved,and the brightness reaches 200 k W/cm~2·str.