Abstract

The nonlinear fibre loop mirror (NOLM) has been shown to be a versatile device for all-optical switching [1], ultrafast multiplexing/demultiplexing [2], logic applications [3], pulse shaping [4] and passive mode-locking for fibre lasers [5]. Initially, the NOLM devices were fabricated using polarisation-maintaining fibres due to concerns about polarisation stability. This can be particularly significant in self switching devices due to differential nonlinear polarisation rotation arising from the unequal powers in the counter-propagating signals. However, the use of polarisation-maintaining fibres is not attractive as coupler fabrication is difficult and a higher loss results when splicing to standard fibres. Recently, stable operation of a dual-wavelength NOLM ultrafast multiplexer/demultiplexer has been demonstrated using 6.4 km long standard telecommunication fibre [6]. In this paper we present experimental results on nonlinear polarisation effects in a self-switching NOLM fabricated from a standard telecommunication fibre.

© 1991 Optical Society of America