| 摘要 |
PROBLEM TO BE SOLVED: To provide an electroabsorption light modulation semiconductor element which reduces a chirp. SOLUTION: Since an intermediate layer 23b is located between a well layer 23a and a barrier layer 23c on the n side of the well layer 23a, the confinement of an electron of a conduction band to the well layer 23a is weakened by the application of a reverse bias, and the peak of the wave functionϕ<SB>e</SB>of the electron shifts toward the intermediate layer 23b. The wave functionϕ<SB>e</SB>of the electron spreads to the well layer 23a and the intermediate layer 23b, and the peak value of the wave functionϕ<SB>e</SB>of the electron becomes low. Meanwhile, since there is no intermediate layer 23b between the well layer 23a and the barrier layer 23c on the p side of the well layer 23a, a heavy hole shifts to the direction opposite to the intermediate layer 23b when a reverse bias is applied in the wave functionϕ<SB>HH</SB>of the heavy hole. The wave functionϕ<SB>HH</SB>of the heavy hole is localized, and the peak value of this wave functionϕ<SB>HH</SB>becomes high. Thereby, the overlap of the wave function of the electron and the wave function of the heavy hole becomes small as a whole. The value of anαparameter further shifts to the negative side by the well layer 23a with compression strain. COPYRIGHT: (C)2008,JPO&INPIT
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