| This thesis presents experimental results in the far infrared response of three different kinds of nanometer scale semiconductor periodic microstructures which are made from the uniform 2DEG's in GaAs/Al{dollar}sb{lcub}0.35{rcub}{dollar}Ga{dollar}sb{lcub}0.65{rcub}{dollar}As heterostructures by further confining or periodically patterning the 2DEG.; The periodic patterns are fabricated by using x-ray lithography and the microstructures are made by transferring the patterns into the 2DEG's. The fabricated and studied structures are: (a) the electron grid/anti-dots and the 2DEG perturbed by a grid potential, described in chapter 3, which are realized by wet chemical etching the wafer masked by a grid metal gate of 0.2{dollar}mu{dollar}m period fabricated on the wafer surface; (b) the 1D wire arrays of 200nm and 300nm periods and the 2DEG perturbed by a 1D potential of 200nm period, described in chapter 4, which are realized by biasing the grating metal gates fabricated on the surface of the sample; (c) the uniform 2DEG's with a grid or grating metal radiation couplers of several different periods, which are described in chapter 5. The grid or the grating gates periodically modulate the FIR radiation incident on the 2DEG. |
