A surgical device is disclosed, and includes a probe having a handle assembly and an electrode assembly extending distally therefrom. An optical member is disposed on the probe and has a first set of light transmitting properties corresponding to a first set of physical parameters of the probe. The probe is configured to transition to a second set of physical parameters, the second set of physical parameters being different from the first set of physical parameters. The optical member is configured to transition from the first set of light transmitting properties to a second set of light transmitting properties, the second set of light transmitting properties corresponding to the second set of physical parameters, the second set of light transmitting properties being different from the first set of light transmitting properties.