Abstract: A laser device includes a laser diode bracket, a photodiode bracket, a laser diode, a photodiode, and an auto power control PCB (automatic power control printed circuit board). The photodiode bracket is configured on the laser diode bracket. The laser diode is configured on the laser diode bracket. The photodiode is configured on the photodiode bracket and on a lateral surface in which the laser diode emits laser a laser beam. In other words, out of a path of an optical axis of the laser beam. The auto power control PCB delivers a driving current such that the laser diode sends one laser beam. The photodiode detects the optical power of the laser beam and generates a feedback signal transmitted to the auto power control PCB for comparison in order to control the stability and reliability of optical output power by the laser diode.