Incoherence device and optical apparatus using same

摘要

An optical member includes: a total reflection mirror including a reflection surface for reflecting a laser beam; a filter including a partially transmissive surface for passing therethrough a part of the laser beam and reflecting the remaining part of the laser beam, the partially transmissive surface being located so as to be opposed to the reflection surface ; and a diffraction grating into which the laser beam enters, for diffracting the incident laser beam to enter the total reflection mirror or the partially transmissive filter.

主权项

1. An optical member, comprising:
a total reflection mirror including a reflection surface for reflecting a laser beam; a filter including a partially transmissive surface for passing therethrough a part of the laser beam and reflecting a remaining part of the laser beam, the partially transmissive surface being located so as to be opposed to the reflection surface; and a diffraction grating into which the laser beam enters, for diffracting the incident laser beam to enter the total reflection mirror or the partially transmissive filter, wherein: the total reflection mirror has an opening for causing the laser beam to enter the diffraction grating; the laser beam enters the opening so as to be perpendicular to the opening; a cross section of the laser beam has a major axis and a minor axis; and the diffraction grating diffracts the laser beam so that a ratio of a length of the minor axis to the major axis in the laser beam exiting from the optical member is larger than a ratio of the length of the minor axis to the major axis in the laser beam entering the diffraction grating.