Phonon-pumped SiGe-Si interminiband terahertz laser

The first phononpumped semiconductor laser has been proposed and theoretica lly investigated. The active region is an unbiased boron-doped Si0.94Ge0.06 /Si superlattice with Si0.97Ge0.03 buffer layers embedded in a surface-plas mon strip waveguide. Warm and cool heat sinks create a temperature gradient across the waveguide. A heat buffer layer adjacent to the cool sink reflec ts optical phonons and transmits acoustic phonons. Within the resonator, th e difference in effective temperatures of optical and acoustic phonons prov ides hole pumping for the lasing transition between the heavy-hole 2 (HH2) and heavy-hole 1 (HH1) minibands. A gain of 280/cm at the 5 THz emission fr equency is predicted for 6 x 10(17)/cm(3) doping at temperatures of 300 K a nd 77 K for optical and acoustic phonons, respectively. A range of operatin g conditions in phonon-pumped IV-IV, III-V, and II-VI materials appears fea sible.