Investigation of heating of silica optical fibers with metal spiral by laser radiation transmitted in the core

The thermo-optical properties of passive silica optical fibers with a metal spiral applied on their lateral polymer surface are investigated. It is shown that the heating of these optical fibers by transmitted laser radiation due to microbending losses causes a change in their temperature and electrical resistance of the metal spiral. Based on this, a simple method for measuring and real-time monitoring the output power of fiber lasers is proposed.