@proceedings {319, title = {Far-infrared harmonic generation from semiconductor heterostructures}, volume = {1854}, year = {1994}, pages = {48-55}, author = {Markelz, A.G. and Gwinn, E. G. and Sherwin, M. S. and Heyman, J. N. and Nguyen, C. and Kroemer, H.} } @proceedings {318, title = {Frequency Dependence of the Third Order Susceptibility of InAs Quantum Wells at Terahertz Frequencies}, year = {1994}, month = {08/1994}, pages = {1193-1196}, author = {Markelz, A.G. and Cerne, J. and Gwinn, E. G. and Brar, B. and Kroemer, H.} } @article {269, title = {GIANT 3RD-ORDER NONLINEAR SUSCEPTIBILITIES FOR INPLANE FAR-INFRARED EXCITATION OF SINGLE INAS QUANTUM-WELLS}, journal = {Solid-State Electronics}, volume = {37}, number = {4-6}, year = {1994}, note = {Sherwin, Mark S/Q-4762-2017
Sherwin, Mark S/0000-0002-3869-1893; Markelz, Andrea/0000-0003-0443-4319
6th International Conference on Modulated Semiconductor Structures
Aug 23-27, 1993
Garmisch partenkir, germany
Tech univ munchen, walter schottky inst
9}, month = {Apr-Jun}, pages = {1243-1245}, abstract = {

Third-order, free-carrier nonlinear susceptibilities, chi(3), have been measured between 19 and 23 cm-1 for three InAs/AlSb quantum wells with sheet densities between 2.5 x 10(12) cm-2 and 8 x 10(12) cm-2. We find that these wells are strongly nonlinear at far-infrared frequencies: odd harmonics ninth order have been observed at high incident intensities, and the peak value of chi(3) reaches approximately 1 esu. This is several orders of magnitude larger than previously reported values for chi(3) in bulk n-GaAs (10(-4) esu)[1] and in polyacetylene (10(-7) esu)[2]. The large magnitude of chi(3) is attributed to the high carrier density in the InAs wells, and to the strong non-parabolicity of the conduction band in InAs. However, the free-carrier chi(3) for bulk InAs predicts a density-dependence different from that observed, and the measured decrease in chi(3) with increasing intensity indicates non-perturbative response. We find that the anisotropy of chi(3) displays the expected 4-fold symmetry.

}, isbn = {0038-1101}, doi = {10.1016/0038-1101(94)90399-9}, author = {Markelz, A. G. and Gwinn, E. G. and Sherwin, M. S. and Nguyen, C. and Kroemer, H.} } @article {267, title = {SUBCUBIC POWER DEPENDENCE OF 3RD-HARMONIC GENERATION FOR INPLANE, FAR-INFRARED EXCITATION OF INAS QUANTUM-WELLS}, journal = {Semiconductor Science and Technology}, volume = {9}, number = {5}, year = {1994}, note = {Sherwin, Mark S/Q-4762-2017
Sherwin, Mark S/0000-0002-3869-1893; Markelz, Andrea/0000-0003-0443-4319
S
8th International Conference on Hot Carriers in Semiconductors
Aug 16-20, 1993
Oxford univ, oxford, england
Sci \& engn res council; royal soc; brit council; oxford univ
4}, month = {May}, pages = {634-637}, abstract = {

Large third-order, free-carrier nonlinear susceptibilities, chi(3) (to approximately 0.2 esu), and subcubic dependence of the third-harmonic power on the incident intensity, have been observed between 19 cm-1 and 23 cm-1 for InAs/AlSb quantum wells with electron sheet densities between 2.5 x 10(12) cm-2 and 8 X 10(12) cm-2. We find that the transmission of the fundamental, and the samples{\textquoteright} DC conductivity, decrease with increasing incident intensity, indicating a large rise in the scattering rate. Using the intensity-dependent transmission to account for absorption in the sample is not sufficient to recover a cubic power law for the third-harmonic intensity. In addition, given the increased scattering rate indicated by the conductivity data, the bulk free-carrier chi(3) due to non-parabolicity should decrease dramatically with increasing fundamental intensity, contrary to our results. Thus, non-parabolicity alone cannot account for the observed third-harmonic response.

}, isbn = {0268-1242}, doi = {https://doi.org/10.1088/0268-1242/9/5S/063}, author = {Markelz, A. G. and Asmar, N. G. and Gwinn, E. G. and Sherwin, M. S. and Nguyen, C. and Kroemer, H.} }