Semiconductor light modulator
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorHitoshi Tada
Life of this patent
Estimating the term…
Abstract
A band discontinuity reduction layer having a band gap energy larger than that of that of an MQW (multiple quantum well) absorption layer and smaller than that of a p-InP clad layer is provided between the MQW absorption layer and the p-InP clad layer. In addition, a band discontinuity reduction layer having a band gap energy larger than that of the MQW absorption layer and smaller than that of an n-InP clad layer is provided between the MQW absorption layer and the n-InP clad layer. Consequently, as a pile-up of carriers is suppressed, a semiconductor light modulator with an enhanced response speed can be obtained.
Claims12
A semiconductor light modulator, comprising:
- a semi-insulating substrate;
- a first conductivity type clad layer formed on said semi-insulating substrate;
- a second conductivity type clad layer having a conductivity type different from that of said first conductivity type clad layer and formed on said semi-insulating substrate in the same height position as said first conductivity type clad layer aligned with a prescribed space;
- an active layer provided between said first conductivity type clad layer and said second conductivity type clad layer;
- and
- a band discontinuity reduction layer provided between said active layer and said first conductivity type clad layer and having a band gap energy larger than that of said active layer and smaller than that of said first conductivity type clad layer.
A semiconductor light modulator, comprising:
- a semi-insulating substrate;
- a first conductivity type clad layer formed on said semi-insulating substrate;
- a second conductivity type clad layer having a conductivity type different from that of said first conductivity type clad layer and formed on said semi-insulating substrate in the same height position as said clad layer aligned with a prescribed space;
- and
- an active layer provided between said first conductivity type clad layer and said second conductivity type clad layer;
- wherein
- said active layer is a multiple quantum well active layer having a barrier layer and a well layer, and includes a mixed crystal portion of said barrier layer and said well layer near the surface of said active layer that faces said first conductivity type clad layer.
A semiconductor light modulator, comprising:
- a semi-insulating substrate;
- a first conductivity type clad layer formed on said semi-insulating substrate;
- a second conductivity type clad layer having a conductivity type different from that of said first conductivity type clad layer and formed on said semi-insulating substrate in the same height position as said first conductivity type clad layer aligned with a prescribed space;
- and
- an active layer provided between said first conductivity type clad layer and said second conductivity type clad layer;
- wherein
- said active layer includes an impurity of said first conductivity type near the surface of said active layer that faces said first conductivity type clad layer.
A semiconductor light modulator, comprising:
- a semi-insulating substrate;
- a first conductivity type clad layer formed on said semi-insulating substrate;
- a second conductivity type clad layer having a conductivity type different from that of said first conductivity type clad layer and formed on said semi-insulating substrate in the same height position as said first conductivity type clad layer aligned with a prescribed space;
- and
- an active layer provided between said first conductivity type clad layer and said second conductivity type clad layer;
- wherein
- said first conductivity type clad layer includes the same substance as a main component of said active layer as a main component.
Dependencies are inferred from the claim text.