LIGHT-TRANSMISSIVE MEMBER, OPTICAL DEVICE, AND MANUFACTURING METHODS THEREOF

摘要

A light-transmissive member has a first principal face, a second principal face, and side faces. The first principal face has a first portion including a center of the first principal face and a second portion between the first portion and the side face sides. The member includes a plurality of altered portions formed between the first principal face and the second principal face so that the plurality of altered portions do not appear on the first principal face, the second principal face, and the side faces. Orthogonal projections of the plurality of altered portions onto the first principal face are included in the second portion.