The invention relates to the optical technology field and discloses a laser. The laser comprises a COS array, a collimating lens array, a reflector array and a shell. When a single-color laser emittedfrom a COS array is emitted through the collimating lens array and the reflector array, parts of light beams are transmitted to a non-planar shell wall of the shell through the reflector array. Due to a fact that the non-planar shell wall of the shell and the light emitted from the reflector array are intersected, the non-planar shell wall and an optical axis are arranged in a non-90-degree mode,transmission light emitted by the reflector array cannot be reflected along an original emitting light path, and chips in the COS array are prevented from being damaged by retroreflection light.