Temperature-stable quantum-dot semiconductor optical amplifier for fixed-wavelength applications using multiwavelength gain compensation

We propose a semiconductor optical amplifier that uses multiple quantum-dot layers with different emission wavelengths to suppress temperature-induced gain variation under a fixed operating current and wavelength. Upon engineering the gain spectrum to offset temperature-driven spectral shifts, the device achieves stable amplification without requiring active temperature control or bias-current adjustment. Experimental measurements show that the gain variation remains within 0.8-0.9 dB over a wide temperature range from 10°C to 85°C. This passive stabilization capability enables reliable operation across harsh outdoor environments, making the device well-suited for LiDAR and outdoor optical communication systems.