Monolithically Integrated InGaAsP/InP 1×2 SOA Optical Switch

摘要

This paper describes a monolithically integrated 1×2 SOA-based switch in InGaAsP/InP. It can be fabricated in one epitaxial growth step, has a footprint of only 4.2mm × 0.35mm, operates on sub-ns time scales and is meant to be integrated with other passive and active waveguide devices on the same InP substrate. The design process optimized the device dimensions using a modified finite-element modal-overlap method. This method provides significant computational savings compared to full beam-propagation method (BPM) simulations. The device uses a single-mode vertical integration technique for a monolithic integration of active and passive waveguide components. To compensate for the polarization sensitivity, tensile-strained quantum well active regions are used. To switch a signal to an output waveguide, the SOA in that waveguide is forward-biased while the SOA in the other output waveguide is reverse-biased to provide a large attenuation ( > 30dB), resulting in minimal crosstalk. This switch has an estimated insertion loss of 4dB, with a polarization dependent loss of < 1dB.