| 摘要 |
PURPOSE:To achieve stable emission in the single axis mode even in high speed modulation by periodically changing the width of an active layer in the direction of beam propagation and making the period several times or less the wavelength of a beam emitted. CONSTITUTION:The basic structure of the embodiment of a 1.3mum band semiconductor laser having an active layer of InGaAsP is buried crescent structure. The width of the active layer is changed by periodically changing the width of a wedge-shaped groove. In this semiconductor laser, the effective refractive index in the active layer changes according to the periodical changes of the width of the active layer 5 to form an internal reflector of high wavelength selectivity. Therefore, a beam can be stably emitted in the single axis mode even in high speed modulation by properly selecting the period of the changes of the width of the active layer. A beam guide layer adjacent to the active layer is not required to enable widening the active layer up to about 2mum for eliminating difficulty in manufacturing. |
