Frequency shift producing device for e.g. lidar, has frequency shift devices with frequency shift elementary modules, where each module has optical fiber whose optical path length is varied with respect to desired frequency shift

摘要

The device has frequency shift devices (11, 11A) with frequency shift elementary modules. Each module has an optical fiber whose optical path length is varied with respect to a desired frequency shift, during each nth pulse of laser beam emission from a laser source (1), where n is greater than or equal to 1. The variation of length corresponds to variation of refractive index of the optical fiber.