Thin-Film Semiconductor Optical Layout for Uniform Current Injection

The single first Mesa structure is divided into multiple second Mesas arranged in the width direction. Each second Mesa has a narrow width (400 nm or less) to maintain strong optical confinement, while multiple Mesas in parallel provide sufficient current injection area for high power output. This segmentation resolves the contradiction by allowing the active layer width to be enlarged without increasing the width of individual Mesa structures that control optical confinement.

Instead of increasing the width of a single Mesa in the lateral direction (which would impair optical confinement), the solution transitions to arranging multiple narrow Mesas in the width direction. This dimensional arrangement allows the total current injection area to increase while each individual Mesa maintains the narrow width needed for optical confinement, effectively solving the contradiction through spatial reconfiguration.

The single current injection path is segmented into multiple independent second Mesa structures distributed across the width of the active layer. Each Mesa provides localized current injection, ensuring uniform carrier distribution across the entire active layer width. This segmentation prevents the non-uniformity problem that occurs with a single wide Mesa or horizontal structure.

Each second Mesa is positioned at specific locations across the width of the active layer to provide localized current injection. This local quality approach ensures that carriers are injected uniformly across the entire width, with each region receiving adequate current supply. The local positioning of multiple Mesas resolves the uniformity issue while enabling high power output across the entire active layer.