Voltage controlled terahertz transmission through GaN quantum wells
  We report measurements of radiation transmission in the 0.220--0.325 THz frequency domain through GaN quantum wells grown on sapphire substrates at room and low temperatures. A significant enhancement of the transmitted beam intensity with the applied voltage on the devices under test is found. For a deeper understanding of the physical phenomena involved, these results are compared with a phenomenological theory of light transmission under electric bias relating the transmission enhancement to changes in the differential mobility of the two-dimensional electron gas. 
T. Laurent, R. Sharma, J. Torres, P. Nouvel, S. Blin, L. Varani, Y.   Cordier, M. Chmielowska, S. Chenot, JP Faurie, B. Beau...
cond-mat.mes-hall