Intersubband nonlinear optical rectification in CdTe/ZnxCd1−xTe/ZnTe asymmetric rectangular quantum wells

The optical rectification (OR) susceptibility of an asymmetric rectangular CdTe/ZnCdTe/ZnTe quantum well (QW) structure is investigated. The asymmetry effect of the potential profile is shown to be barely noticeable on the ground level, however its effect is much stronger in the first excited state. The behavior of OR coefficient M212(M22 − M11) gradually decreases with increasing well width or x composition because of the reduced asymmetry. Also, the OR the coefficient decreases very rapidly with increasing well width because the term M212(M22−M11) decreases with increasing well width Lw. The OR coefficient decreases with increasing composition x and its peak energy is blueshifted. If very large OR coefficients are to be obtained, the use of thin well widths with smaller composition x is desirable.