Optical modulator

Abstract

Abstract PURPOSE:To suppress the influence of a deep electron capturing level in InAl As so as to obtain a large on/off ratio and to enable low-voltage driving as well by adopting a multiple quantum well structure for which a barrier layer consisting of InGaAs/InP in place of using a single material as a barrier layer. CONSTITUTION:This optical modulator has the multiple quantum well MQW structure 13 formed of the barrier layer having the form of sandwiching in InP layer 5 with thin InAlAs layers from both sides and an InGaAs well layer. Since the InAlAs layers and the InP layers 5 to constitute the barrier layer have band gaps in conduction band and valence electron band when these layers are joined. The conduction band discontinuities of the well layers/barrier layers are 0.50eV and a quantum effect is easily expectable if such MQW structure 13 is used. In addition, the influence of the deep level in the InAlAs of the barrier layers 2 decreases. The voltage to be impressed to a diode is thereby lowered and the optical modulator having the large on/off ratio is obtd.

Inventors

• 👤 Shunji Nojima

Bibliographic Details