Optical time domain reflectometer, optical fiber detection system, optical communication system and communication equipment

The invention discloses an optical time domain reflectometer, an optical fiber detection system, an optical communication system and communication equipment, and belongs to the technical field of optical fiber detection. The optical time domain reflectometer comprises a light emitter, a detector, a combiner/splitter, a first interface and a second interface, the multiplexer/demultiplexer is located on an emission light path of the light emitter, the detector is located on an emergent light path of the multiplexer/demultiplexer, the first interface is located on the light path of the multiplexer/demultiplexer, and the second interface is located on an incident light path of the multiplexer/demultiplexer; the first interface is connected with an optical interface of an optical device, and the second interface is used for insertion of a to-be-tested optical fiber. No matter whether the optical time domain reflectometer is in a detection state or not, the optical time domain reflectometer and the optical device a