| 摘要 |
PURPOSE:To provide the multiquantum well structure optical modulator which is high in speed and low in chirping. CONSTITUTION:The electric field absorption type optical modulator for which a light absorption layer 103 of a multiquantum well structure is adopted is advantageous in terms of low voltage driving, low insertion loss, etc. The phenomenon called as pile up that the carriers generated in the process of light absorption are accumulated in the multiquantum well is liable to arise and the transmission characteristic at the time of high speed modulation is deteriorated by this phenomenon. The optical modulator with which the carriers are easily withdrawable and which can make high-response is obtd. by adopting the structure formed in such a manner that electrons and light holes are formed in place of the electrons and heavy holes in the process of light absorption and transition and the structure in which resonance tunneling arises to lighten the effective mass by noticing the accumulated carriers, particularly the holes. |
