Two-way transmission optical current sensor

A two-way transmission optical current sensor relates to a sensor, for solving the problems of difficult packaging and weak environmental tolerance of one in and two out optical path structure of the prior optical current sensor. The optical current sensor comprises an optical sensor, three couplers, a light source, a first detector and a second detector. The first coupler has a first port connected with an output end of the light source, a second port connected with a second port of the second coupler, and a third port connected with a second port of the third coupler. The second coupler has a first port connected with one input/output end of the optical sensor, and the third coupler has a first port connected with the other input/output end of the optical sensor. The second coupler has a third port connected with an input end of the first detector, and the third coupler has a third port connected with an input end of the second detector. The invention is used for measuring currents, can bidirectionally transmit optical signals, is easy to package, and has strong tolerance to environmental change.