Patent ID: 7881567

Claim:
An optical device for monitoring a rotatable shaft with an oriented axis, comprising: an optical waveguide having an optical sensor arranged on the rotatable shaft, the optical sensor being interrogated via the optical waveguide by a light signal; a transceiver unit arranged in a fixed location relative to the rotatable shaft, the light signal being emitted by the transceiver unit; a transmission unit, the light signal being transmitted between the transceiver unit and the optical waveguide by the transmission unit, the transmission unit having a first multimode optical waveguide arranged at a fixed location in relation to the rotatable shaft and assigned to the transceiver unit with an assigned first coupling device and a second multimode optical waveguide arranged on the rotatable shaft eccentric to an axis of the rotatable shaft and connected to the optical waveguide with an assigned second coupling device; and an evaluation unit assigned to the transceiver unit for determining a physical variable from a light signal originating from the optical sensor and transmitted by the transmission unit, wherein the light signal is transmitted via the first and second coupling devices between the first and second multimode optical waveguides.