A laser illuminator comprising at least one optical diffusion means capable of modifying an optical diffusion condition (3) and at least one optical suppression means for suppressing divergence of light (100), wherein the optical diffusion means and the optical suppression means are disposed along an optical path of a laser beam (6) radiating from a laser source and the laser beam is converted into a diffused and non-divergent light beam (6-2) for illuminating or exciting an object by passing through the optical diffusion means and the optical suppression means.