Optically induced Kerr phase shifting in optical fibre gates at diode laser pump powers

Fast all-optical signal processing devices are desirable for use in high speed optical communications systems. The optical Kerr effect has the potential for a wideband, ultrafast response. Because of this, Kerr effect devices have been considered for all-optical signal processing applications. To date a number of all optical Kerr devices have been demonstrated. These include an all-fibre logic `AND´ gate and a Kerr modulator. Commercial applications of such devices are much more likely if diode lasers could be used to provide these high intensities. The authors summarise work on two types of modulator that are pumped by a diode laser. The first is based on the nonlinear Mach Zehnder interferometer structure and the second uses polarisation rotation in a single birefringent fibre