Example of FEL
THz sideband generation |
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•Electorn-hole recollisionunder intense THz field results in high number of side bands generation
•Precise imprint of THz frequency on the NIR laser carrier
Excitonsin the quantum well are resonantly induced with the aid of the near-IR laser. External THz field modulates excitonpotential landscape resulting in transfer of THz quanta to the excitonicstate. In the process of radiative decay the near-IR fundamental as well as multiple sidebands are emitted. References 1. B. Zaks, R.B. Liu, and M.S. Sherwin “Experimental observation of electron-hole recollisions” Nature, 483, 580-583 (2012). 2. H. Banks, B. Zaks, F. Yang, S. Mack, A.C. Gossard, R. Liu, and M.S. Sherwin “Terahertz electron-hole recollisionsin GaAs/AlGaAsquantum wells: robustness to scattering by optical phonons and thermal fluctuations” Phys. Rev. Lett. 111, 267402 (2013). |
THz harmonics generation |
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•Harmonic generation in THz extends available frequency range
•High FEL power results in effective conversion ratio
Third harmonic generation in highly reflective InAsand Si semiconductor wafers.
References 1. I. Al Naib, J.E. Sipe, and M.M. Dignam(arXiv:1407.1273 [physics.optics], 2014). 2. D. Valovcin, M.S. Sherwin, work in progress. |