Patent ID: 8305563
Filing Date: 2012-11-06
Classification: G01S

Abstract:
1. An electro-optical distance-measuring unit, comprising: a light source, the emitted light of which in the distance-measuring unit is guided onto a measurement path at least by a polarizing beam splitter, an electro-optical modulator and a lambda/4 retarder, and light returning along the measurement path is guided onto a detector at least by the retarder, the electro-optical modulator and the polarizing beam splitter, and an evaluation unit for determining a length of the measurement path in accordance with a modulation frequency of the electro-optical modulator and a signal of the detector, wherein the light source has a broad spectrum of the emitted light, and wherein a bandwidth Δλ of the light source satisfies the following condition where n o is the ordinary and n e the extraordinary wavelength-dependent refractive index of the modulator material, I crystal is the length of the modulator crystal and λ is the wavelength of the light source.