Optimal design of the gain bandwidth of vertical-cavity semiconductor optical amplifiers based on the couple cavities

The bandwidth of the vertical-cavity semiconductor optical amplifiers(VCSOAs) is commonly narrow.A VCSOAs using a coupled-cavity design to broaden the bandwidth is proposed.The coupled-cavity is made by changing the structure of the distributed Bragg reflector(DBRs) on one side of the active region to construct the passive cavity coupled with the active region.Based on this model and under the reflection mode,the characters of the gain bandwidth of the two cavities and three cavities structure are calcucated.With the transfers matrix method.It is found that the bandwidth is increased to above 3nm at the 10dB peak gain level.It has a great improvement compared to simple cavity structure.