The applications field of the optocouplers, in the case when the user has access to the optical path of the light beam, becomes larger and larger. Polaroid optocoupler LED–phototransistor is a device in which it is introduced a system of polaroid filters, on the path of the light beam that performs the optical coupling between the transmitter and receiver modules. By introducing this system of polaroid filters, one can modify the intensity of the output current as a consequence of an axial rotation movement, of the receiver module towards the emitter module. Such a device can be used both as a mechanic-electrical transducer and as a mechanic-electrical modulator. The device is designed for applications both in the field of robotics and of mechatronix.