Absolute distance measuring device with optical switch

摘要

An absolute distance measuring device which determines a distance to a target (26) comprises: a light source (102) emitting an emitted light beam (108, 46); a fiber switch network (200) having at least one optical switch (500) at least switches between two positions in response to a switch control signal, wherein a first one of the positions activates a measurement mode in which the emitted light beam (108, 46) is emitted from the fiber switch network (200) to the target (26) and as a measuring light beam (48). is reflected back into the fiber switch network (200), a second of the positions activating a reference mode in which the light beam has a reference light beam within the fiber switch network (200), the fiber switch network (200) further comprising a sub-fiber retroreflector (505) and at least a fiber optic coupler (206), through which the emitted light beam (108, 46) and the measuring (48) u a single channel detector (322) which detects the measurement (48) and reference light beams in a temporally spaced, multiplexed manner and provides an electrical signal corresponding to the detected measurement (48) and reference light beams, the at least one fiber optic coupler (206) is optically coupled to the single channel detector (322), to the light source (102) and to the at least one optical switch (500); a single channel signal processor (324, 3000) which processes the electrical signal and a conditioned electrical signal in response thereto, anda data processor (400) processing the conditioned electrical signal to determine the distance to the target (26), wherein in the measurement mode the emitted light beam (108, 46) from the light source (102) passes through the at least one fiber optic coupler (206) to the at least one optical switch (500) located in the measurement mode pos and the measurement light beam (48) from the target (26) through the at least one optical switch (500) located in the measurement mode position and through the at least one fiber optic coupler (206) and passed to the single channel detector (322); and in the reference mode, the emitted light beam (108, 46) from the light source (102) through the at least one fiber optic coupler (206) to the at least one optical switch (500) located in the reference mode position and to the sub-fiber retroreflector (505), and wherein the reference light beam reflected from the sub-fiber retroreflector (505) is transmitted through the at least one optical switch (500) located in the reference mode position and through the at least one fiber optic coupler (206). and to the single channel detector (322).