Enhancement of birefringence in polarisation-maintaining fibres by thermal annealing

Abstract

The thermal behaviour of highly birefringent polarisation-maintaining optical fibres is studied, and the thermal hysteresis of the birefringence is related to the quenching of the fibre. Suitable ‘on-line’ thermal annealing during fibre drawing is shown to be a method for the full development of the high anisotropic stresses potentially available in high birefringence structures using borosilicate stress-producing parts.