摘要 |
There is provided an optical semiconductor device having a first optical semiconductor element including an InP substrate, a lower cladding layer formed on the InP substrate, a lower optical guide layer which is formed on the lower cladding layer and is composed of AlGaInAs, an active layer which is formed on the lower optical guide layer and has a multiple quantum well structure where a well layer and a barrier layer that is formed of AlGaInAs are alternately stacked, an upper optical guide layer which is formed on the active layer and is composed of InGaAsP, and an upper cladding layer formed on the upper optical guide layer. |