Abstract: A method of manufacturing an optical device includes: a first step of forming an optical-device forming body that includes a plurality of columnar structures arranged in an arrangement direction on a substrate surface via a trench and an outline structure connected to and containing therein the plurality of columnar structures; a second step of oxidizing the optical-device forming body from a state where the optical-device forming body starts to be oxidized to a state where the columnar structure is oxidized; and a third step in which an unoxidized residual part of the outline structure in the second step is oxidized after the second step so as to form an oxidized body. Furthermore, the third step includes restraining the outline structure from being deformed with respect to at least the arrangement direction of the columnar structures in the third step.

Abstract: A radar apparatus has a light receiver that includes a refractive body and a mirror on an opposite surface of the refractive body relative to an incidence surface of the refractive body for receiving an incident light from an outside of the radar apparatus. The refractive angle of the refractive body is configured to be smaller than an incident angle of the incident light, and the mirror is configured to reflect at least a portion of the incident light toward a first light receiving element that is disposed on the incidence surface with its light receiving face facing the incidence surface of the refractive body.

Abstract: A radar apparatus has a light receiver that includes a refractive body and a mirror on an opposite surface of the refractive body relative to an incidence surface of the refractive body for receiving an incident light from an outside of the radar apparatus. The refractive angle of the refractive body is configured to be smaller than an incident angle of the incident light, and the mirror is configured to reflect at least a portion of the incident light toward a first light receiving element that is disposed on the incidence surface with its light receiving face facing the incidence surface of the refractive body.

Abstract: A method of manufacturing an optical device includes: a first step of forming an optical-device forming body that includes a plurality of columnar structures arranged in an arrangement direction on a substrate surface via a trench and an outline structure connected to and containing therein the plurality of columnar structures; a second step of oxidizing the optical-device forming body from a state where the optical-device forming body starts to be oxidized to a state where the columnar structure is oxidized; and a third step in which an unoxidized residual part of the outline structure in the second step is oxidized after the second step so as to form an oxidized body. Furthermore, the third step includes restraining the outline structure from being deformed with respect to at least the arrangement direction of the columnar structures in the third step.