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

In this talk I will discuss the use of dark spatial solitons to write reconfigurable waveguide devices into defocusing 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