Thermal transients of coated optical fibres exposed to microwave power at 2.45 GHz

Measurements are made of the thermal response of coated single-mode optical fibres to microwave power at 2.45 GHz using an all-fibre Mach-Zehnder interferometer. A carbon based secondary coating has been used as the energy absorbing medium. Computer based analysis of the thermal transient includes consideration of thermal conduction within the fibre together with both radiative and convective heat losses at the outer surface. A simplified treatment of the convection loss has been employed, in which the convective heat transfer coefficient is assumed to be constant during the thermal transient. The predictions of the adopted model are compared with measurements, the degree of agreement justifying the model. A convective process is identified as the dominant heat loss mechanism