An optical component or optical low-pass filter has two or more regions demarcated by differences in refractive indexes, in which a region having a refractive index different from the refractive index of the continuous region with the largest volume among the two or more regions is formed in the interior of a transparent material. This optical component or optical low-pass filter has regions with different refractive indexes formed in the interior by pulsed laser irradiation or focused irradiation of the transparent material.