OPTICAL APPARATUS, AND ON-VEHICLE SYSTEM AND MOVING APPARATUS INCLUDING THE SAME

An optical apparatus includes a deflection unit configured to deflect illumination light from a light source to scan an object and deflect reflected light from the object, and a light guide unit configured to guide the illumination light from the light source to the deflection unit and guide the reflected light from the deflection unit to a light-receiving element, wherein the light guide unit includes a first surface on which the illumination light from the light source is incident and a second surface including a transmissive region through which the illumination light from the first surface is transmitted and a reflective region that reflects the reflected light from the deflection unit, wherein the first and the second surfaces are non-parallel to each other, and wherein the illumination light from the first surface is incident on the transmissive region without passing through other surfaces.