| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a parasitic capacitance while suppressing overflow of a ridge type DML.SOLUTION: A direct modulation laser has a ridge type waveguide formed on an n-InP substrate; and includes an MQW structure formed of an InGaAlAs material, a non-doped semiconductor layer formed of an InGaAsP material on the upper layer of the MQW structure, a p-doped semiconductor layer formed of the InGaAlAs material or an InAlAs material on the upper layer of the non-doped semiconductor layer, and a p-InP clad layer on the upper layer of the p-doped semiconductor layer. A waveguide portion of the ridge type waveguide includes the p-doped semiconductor layer and the p-InP clad layer, and has a resonator length of 100μm to 200μm.</p> |
