All Gain chips (RSOA, SOA)

Gain chips, also known as semiconductor optical amplifier (SOA) or reflective semiconductor optical amplifier (RSOA), are semiconductor laser components designed to operate as the gain medium in an external cavity rather than as a complete laser on their own. A low-reflectivity output facet prevents lasing within the semiconductor, while optical feedback from the external cavity provides laser operation. This approach enables wide wavelength tuning and narrow linewidth operation, while allowing the gain chip to be integrated into photonic circuits with tailored beam shapes and positions.