Silicon waveguided components for the long-wave infrared region

We propose that the operational wavelength of waveguided Si-based photonic integrated circuits and optoelectronic integrated circuits can be extended beyond the 1.55 mu m telecom range into the wide infrared from 1.55 to 100 mu m. The Si rib-membrane waveguide offers low-loss transmission from 1.2 to 6 mu m and from 24 to 100 mu m. This waveguide, which is compatible with Si microelectronics manufacturing, is constructed from silicon-on-insulator by etching away the oxide locally beneath the rib. Alternatively, low-loss waveguiding from 1.9 to 14.7 mu m is assured by employing a crystal Ge rib grown directly upon the Si substrate. The Si-based hollow-core waveguide is an excellent device that minimizes loss due to silicon's 6-24 mu m multi-phonon absorption. Here the rectangular air-filled core is surrounded by SiGe/Si multi-layer anti-resonant or Bragg claddings. The hollow channel offers less than 1.7 dB cm(-1) loss from 1.2 to 100 mu m.