We report the operation of a Bloch oscillator. The active medium was a staticvoltage driven, doped GaAs/AlAs superlattice which was electromagnetically coupled to a resonator. The oscillator produced tuneable microwave radiation (frequency ~ 60 GHz; power ~ 0.5 mW; efficiency ~ 4 %). The gain (~ 10^4 /cm) was due to the nonlinearity mediated by miniband electrons. We also present a theory of the oscillator. The Bloch oscillator should in principle be feasible for generation of radiation up to frequencies of 10 THz and more.
@article{arxiv.cond-mat/0502283,
title = {Operation of a Bloch oscillator},
author = {K. F. Renk and A. Meier and B. I. Stahl and A. Glukhovskoy and M. Jain and H. Appel and W. Wegscheider},
journal= {arXiv preprint arXiv:cond-mat/0502283},
year = {2007}
}