Active multi-mode interferometer semiconductor optical amplifier on quantum dots toward high saturated output power under high temperature

Semiconductor optical amplifier (SOA) is wildly used as gain media in photonic integrated circuit, as it is integrable with various devices, including wavelength filter, on a same wafer. Quantum dot (QD) has been known to realize high temperature operation without using thermo-cooler, the saturated output power was not high due to the limited density of state in QD. To realize high saturated output power under high temperature, we have exploited active multi-mode interferometer (active-MMI) configuration on QD SOA. We fabricated active-MMI SOA using 1.31 μm InAs/GaAs quantum-dot active layer with the design of approximately 5 times larger footprint compared to single-stripe, whereas it holds regular single transverse mode output. As a result, significant improvement of 15 dB saturated output power at 75℃ was substantiated successfully.