3.5 Thz Quantum Cascade Laser at 70 K as Local Oscillator
Author(s)Ren, Y.; de Visser, P. J.; Hovenier, J. N.; Zhang, W.; Gao, J. R.; Klapwijk, T. M.; Shi, S. C.; Kao, T.-Y.; Kumar, S.; Reno, J. L.; Hu, Qing; ... Show more Show less
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We report a set of measurements to demonstrate a new type of surface emitting distributed feedback (DFB) quantum cascade laser (QCL) operated at 3.5 THz as a local oscillator by pumping a superconducting hot-electron bolometer (HEB) mixer. Based on the Bragg gratings incorporated into the waveguide, the second order DFB surface emitting THz QCL shows single mode emission at 3.555 THz, which is only 4 GHz off from the hydroxyl (OH) line. Because of the radiation being emitted from the surface, the far-field beam is much improved, with a divergent far field beam pattern only in one direction. We also notice that in the far field beam pattern, unlike conventional metal-metal waveguide QCLs, there are no interference patterns. All these factors make it possible to fully pump a superconducting NbN HEB mixer at 60 K, and even at 70 K based on the estimated power.
DepartmentMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Proceedings of the 22nd International Symposium on Space Terahertz Technology
Ren, Y., et al. "3.5 Thz Quantum Cascade Laser at 70 K as Local Oscillator." 22nd International Symposium on Space Terahertz Technology (April 2011).
Author's final manuscript