| 摘要 |
PURPOSE:To increase the light emitting and absorbing efficiencies of the title element by using such a quantum well structure that the interface between a well and barrier layers is constituted of an inclined layer having a continuously varying forbidden band width. CONSTITUTION:A barrier layer 51 is made of InP and a well layer 52 is composed of an InGaAs layer 53 and inclined layer 54. The composition of the inclined layer 54 gradually changes from InGaAsP to InGaAs. After an n-InP clad layer 20, quantum well structure 50, p-InP clad layer 60, and p-InGaAsP contact layer 70 are formed on an n-InP semiconductor substrate 10, a multiplexed quantum well optical modulator having such structure is buried by means of high-resistance InP (Fe-doped) 80. By using such structure, an optical modulator which is low in driving voltage and has an excellent damping ratio is obtained. In other words, a high-performance element having a quantum well structure which is high in light emitting and absorbing efficiencies can be obtained. |
