| 摘要 |
<p>PURPOSE:To obtain a high response speed with a semiconductor having quantum well structure by adding an impurity to nearly the central part of the semiconductor part which is a quantum well and generating an optically nonlinear characteristic at the wavelength resonating with the bound exciton incidental to said impurity. CONSTITUTION:A is a GaAs layer, B is an AlGa layer and 1 is the impurity doped in a sheet shape in the quantum well structure constituted of GaAs and AlGaAs. Since the radius of the barycentric motion of the bound exciton incidental to the impurity 1 is considered approximately several tens Angstrom , the max. doping race density is estimated to be about 10<12>cm<-2>. If the thickness of the quantum well layer is 100Angstrom , the cubic nonlinear sensitivity chi<(3)> attains about 10<-3>esu value. In addition, the radiation life of the bound exciton is from 1 nanosecond to sub-nanosecond and, therefore, the semiconductor which responds at a high speed and has the large optical nonlinearity is obtd.</p> |
