| 摘要 |
<p>PURPOSE:To realize a high extinction ratio with a low impressed voltage by specifying the P compsn. of InGaAsP layers of quantum well layers and the thickness of one layer. CONSTITUTION:The multiple quantum well layers 11 formed by alternately laminating plural times the InGaAsP layers and InP layers subjected to lattice matching on an InP substrate 13 and two electrodes 8, 9 on both sides of the well layers 11 are provided and the prescribed AC voltage is impressed thereto. The P compsn. of the InGaAsP layers is specified to 1-20at.% and the thickness of the one layer to a 60-200Angstrom range. For example, the P compsn. is specified to 6.5at.% and the thickness of the one layer to 81Angstrom . As a result, 20dB extinction ratio is attained by 0.6V impressed voltage and the remarkable performance improvement as compared to 7V heretofore is attained.</p> |
