This work demonstrates a rib waveguide photodetector based on a vertical Si p-i-n junction with Ge islands operating in the spectral region around λ=1.55 μm at room temperature. A vertical stack of four layers of Ge islands is grown by molecular beam epitaxy on a silicon-on-insulator. Each layer is organized in a two-dimensional square grid with a period of 460 nm. The spectral response of the detector extends well beyond 1.6 μm at 300 K. The absorption length of ~135 μm (at 1/e decrease of intensity) at λ=1.55 μm along the waveguide allows for relatively small-size devices for all-on-one-platform integration.
© 2009 Optical Society of America
Original Manuscript: September 29, 2009
Manuscript Accepted: October 31, 2009
Published: December 3, 2009
Ventsislav Lavchiev, Roman Holly, Gang Chen, Friedrich Schäffler, Rüdiger Goldhahn, and Wolfgang Jantsch, "Si rib waveguide photodetector with an ordered array of Ge islands for 1.5 μm," Opt. Lett. 34, 3785-3787 (2009)