Prospects for photonic circuits written by dark spatial solitons in defocussing non-linear materials

Abstract

In this talk I will discuss the use of dark spatial solitons to write reconfigurable waveguide devices into defocussing non-linear media. Compared with bright spatial solitons, dark solitons are particularly simple optical structures characterised by an abrupt change in the transverse phase structure of an optical wave at some boundary. Dark spatial solitons are simply regions of total or partial destructive interference between the waves on either side of this boundary, with the size of the structure being stabilised by the non-linear propagation within the medium in which they are created. Of great relevance when using dark spatial solitons to write optical switches, is the fact that the direction of propagation of the soliton is determined by the magnitude of the phase change at the boundary (it is also affected by the intensity distribution of the soliton forming beam). Hence by changing the phase (or the intensity distribution) the soliton can be steered over a wide range of angles. By this means the induced waveguide can also be steered allowing the information carrying beam to be directed from an input `port' to one of several output 'ports'. Show more