Based on plasma dispersion of Si1-xGex, the single mode waveguide modu
lators consisting of Si1-xGex/Si and Si/Si1-xGex/Si which were grown b
y molecular beam epitaxy have been fabricated. For Si1-xGex/Si structu
re, the switch current and insertion loss at wavelength 1.3 mu m are 3
6 mA and 2.8 dB. respectively The switching response time is 40 ns.