All-optical switching operating at 1.55 µm band in fabricated GaInAsP directional couplers loaded with grating are reported experimentally. These switching operations were realized in spatially separated output ports. The devices are suitable for optical integrated circuits and would operate as all-optical routing switches in practical power level by use of optical Kerr effect and Bragg grating. Using the optical bistability in the device, latching operation for output signal can be realized in spatially separated output ports and the outputs from each port are complementary. Two all-optical gate operations, which are optical inverting operation and optically controlled switching in spatially separated output ports, are also demonstrated, where the signal and control lights have different wavelength.

We describe a simple all-optical wavelength converter based on a Fabry-Perot semiconductor optical amplifier (FPSOA). We measure its static characteristics in detail and successfully demonstrate its dynamic wavelength-conversion operation (both inverted and non-inverted) at 2.5 Gbit/s. This is the first demonstration of FPSOA-based wavelength conversion. Quasi-digital response is also observed. Low input power, ease of fabrication and good compatibility with WDM networks are important advantages of FPSOA.