Temperature dependence of gain in a highly stacked quantum dot semiconductor optical amplifier

We investigated the temperature characteristics of a modularized semiconductor optical amplifier (SOA) utilizing InAs/AlGaAs quantum dot (QD) in the active layer operating at C-band (1.53 mu m-1.56 mu m). It has been reported by many literatures on physics that QDs are superior at energy efficiency and leads to less thermal energy generation. By changing the temperature of the Peltier element inside the module from 20 degrees C to 80 degrees C, we measured the difference in the gain at each input power and injection current. The QD-SOA we measured was utilizing InAs QD in active layer and the laminated structure had 20 layers having 20nm of intermediate layers which refers to the width between QDs. When the input power was -50 dBm, we successfully confirmed more than 10 dB at the Peltier element temperature of 70 degrees C by injecting a current larger than 400 mA. In addition, we obtained a maximum gain of 20.68 dB at the center wavelength and a constant gain of approximately 15 dB at other Peltier element temperatures. It can be concluded from the output of the experiment that this QD-SOA can be put to use in optical communication in several situations where the temperature ranges between 20 degrees C to 80 degrees C. This involves a new approach towards the application of QD amplifiers in the field of optical fiber communications.