Optical fibre polariser based on GRIN single crystal fibre

A novel optical fibre polariser based on a GRIN crystal fibre and suitable for in-line use with singlemode optical fibre is described and demonstrated in a proof of principle experiment. Using fibres of alpha-axis lithium nio bate, grown by the laser healed miniature pedestal growth method and heat t reated to produce radial extraordinary refractive index gradients, one plan e of polarisation is coupled through the system while the orthogonal is rej ected. Extinction ratios of up to 1200 (31dB) have been obtained at 632.8nm .