The principle of the semiconductor module is the excitation mode. The semiconductor material (using electrons) is used to jump between the energy bands, and the cleavage plane of the semiconductor crystal is used to form two parallel mirror surfaces as mirrors to form a resonant cavity, so that the light oscillates, feedbacks, The radiation that produces the light is amplified and the laser is output. The advantages of semiconductor module lasers are small size, light weight, reliable operation, low power consumption and high efficiency.