The Effect of Double-Pass Gain on the Performances of a Quantum-Dot Superluminescent Diode Integrated With a Semiconductor Optical Amplifier

We fabricate a quantum-dot (QD) superlumenescent diode (SLD) integrated with a semiconductor optical amplifier (SOA). The integrated device exhibits coordinative working between the SLD and SOA when the two sections are pumped with a series of different currents. However, the SLD source affects the device behavior not via the amount of energy supplied by itself, but via an existing double-pass gain throughout the whole structure. With the help of a QD device model, this behavior is numerically analyzed which explains the origin of competition between different QD states in the emission spectra as well as the strong power-control capability of the SLD source.