The scheme of an external semiconductor laser with built-in microstructure fiber is designed and studied to achieve fiber-side lighting. This scheme solves the problems associated with traditional direct down liquid crystal modules: these require a large number of light-emitting diode chips, and the volume of the built-in semiconductor laser scheme is too large. The effects of different depths, radii, and the number of microstructures on the optical field are simulated and analyzed. Light field with a peak illumination of 32650 lx, a horizontal viewing angle of 85°, and a vertical viewing angle of 84°33′35″ is obtained. These values meet the requirements of the liquid crystal display (LCD) industry for achieving a peak backlight illumination of 10000 lx, a horizontal viewing angle of 60°, and a vertical viewing angle of 50°. The proposed scheme provides a new method for applying semiconductor lasers in the field of LCD display.