A 2 × 2 optical switch based on plasma dispersion effect in silicon-on-insulator

Based on Mach-Zehnder interferometer (MZI) structure, a 2 × 2 optical switch is fabricated on SOI wafer. Modulation of the refractive index of MZI arms is achieved through free carriers plasma dispersion effect of silicon. The device presents an insertion loss as low as 3.44 dB and a response time as small as 300 ns. The crosstalk and extinction ratio are −15.54 and 14.9 dB, respectively. Detailed analysis and explanation of the operating behaviors are also presented.