Dispersion measurement of the semiconductor optical amplifiers

The semiconductor optical amplifier (SOA) is a key device for all optical signal processing based on its nonlinearity, which depends on its group velocity dispersion (GVD). A simple scheme to measure the GVD of the SOA is proposed with some computations from the measured gain spectra based on the relationship between GVD and the optical gain from the Kramers-Kronig relation. The dispersion is relatively flat in the range of 1530 nm~1610 nm, and lightly depends on the input power and the injection current. The peak-gain wavelength and zero-dispersion wavelength red-shift with the input power increasing and blue-shift with the injection current increasing, and the zero-dispersion wavelength is greater than the peak-gain wavelength on the longer wavelength side.