High photoconductive gain in Ge(x)Si(1-x)/Si strained layer superlatice Detectors Operating at lambda = 1.3microns.

We demonstrate high photoconductive gain in Ge(x)Si(1-x)/Si strained layer superlattice detectors grown by molecular beam epitaxy. The gain mechanism is considered to be the preferential hole trapping in the Ge(x)Si(1-x) wells. Ge0.6Si0.4 waveguide devices operating at the wavelength of 1.3microns show optical gain as large as 40 at a low bias of 5-7V and gain bandwidth product as large as 3.6GHz. Preliminary bit error experiments show sensitivity sufficient for transmission at distances of over 25km and data rates of 200Mb/s.