Novel gain measurement method without optical fiber alignment in a semiconductor optical amplifier

A novel chip gain measurement method for semiconductor optical amplifiers (SOAs) eliminates the need for fiber alignment. The chip gain is clarified based on amplified spontaneous emission (ASE) power measurement through an optical bandpass filter. We clarified the validity of the method theoretically, and successfully demonstrated gain measurement, comparing it with the conventional method with fine fiber alignment. The results agree well, within an error of 1 dB.