<title>Building blocks for a 10 x 10 crossbar switch based on GaAs/GaAIAs channel waveguide array</title>

Abstract

In this paper, we proposed an all-optical crossbar switch based on a successfully demonstrated optically activated modulator (OAM). This modulator was based on a GaAlAs/GaAs channel waveguide and waveguide array. A schematic of the demonstration is shown in Figure 1. A 5 micrometers activation window was employed to input an approximately mW HeNe 632.8 nm light which, in turn, modulates the 1.3 micrometers guided light. Modulation depths from 33% to 85% have been observed on the various devices tested. The size of the activation window is much smaller than for a linear electro-optic device (approximately mm to approximately cm) and a high power laser was not used in this demonstration. Consequently, this constitutes proof that a much more practical crossbar based on GaAs/GaAlAs channel waveguides can be built. The device architecture for the all-optical low-threshold 10 X 10 crossbar switch is shown in Fig. 2 where semiconductor laser diode arrays with wavelength shorter than the band gap of GaAs semiconductor are employed to optically switch the propagation directions and thus receiving ports. Refractive index modulation as high as 10<SUP>-2</SUP> was achieved. Therefore, up to 100% on/off switching can be achieved within an activation length of 20 micrometers .