|Publication No: 212||Search all ORC publications|
Polarisation in fused single mode fibre couplers
F.P.Payne, C.D.Hussey, M.S.Yataki
The first polarisation beam splitter based on a single-mode fused-taper coupler has been recently demonstrated. In the device it was shown that the frequency response of the coupling of unpolarised light exhibits a modulated oscillatory behaviour. The modulation occurs because the coupling strengths of x- and y-polarised light are slightly different, resulting in different beat lengths for the two polarisations. Potentially there are many important applications which can exploit this effect. These include wavelength filters, multiplexers, modulators, and wavelength tuneable couplers. The ease and simplicity of fabrication of the fused coupler is an added advantage when considering such applications.
In this paper we present further results which demonstrate that the polarisation splitting ability arises predominantly from geometrical birefringence in the coupling region. This conclusion is supported by a detailed analysis of the birefringence which is in good agreement with our experimental measurements.
5th European Conference on Optical Communication (ECOC) Venice Oct (1985) pp.571-574
Copyright University of Southampton 2006