Single-wavelength emission device

摘要

This device comprises an optical source emitting a single-wavelength light beam. An index grating has been recorded in a holographic device by the interference of two plane light beams, both being beams at a single wavelength with one and the same determined value and being concurrent in the holographic device. The holographic device is illuminated by the light beam and delivers a single-wavelength beam whose radiation pattern has a limited angular passband. The wavelength of the reading beam may be different from that of the recording beams. Its orientation is then different from that of the beams.