A structured light generation device includes a laser light source module and a diffractive optical element. After a non-collimated light beam from the laser light source module is received by a diffraction layer of the diffractive optical element, the non-collimated light beam is modulated as an optical information-bearing light. Since no collimator is between the laser light source module and the diffractive optical element, the spacing distance between the laser light source module and the diffractive optical element is shortened. Consequently, the overall structured light generation device is slim.