Strained Si1−xGex multi‐quantum well waveguide structures on (110) Si

Pseudomorphic Si1−xGex/Si multi‐quantum well structures for waveguide applications have been grown on (110) Si by molecular beam epitaxy. In a series of samples the Ge fraction x has been varied from x=0.25 to x=0.37 and x=0.50, respectively. We have used photocurrent spectroscopy on mesa diodes to demonstrate that the absorption edge of the strained Si1−xGex quantum wells can be tuned from 1.3 to 1.55 μm by the Ge fraction x. Realization and characterization of single‐mode (110) Si1−xGex rib waveguides with end facets of high optical quality, prepared by cleaving, is reported.