C+L BAND SOA MULTI-WAVELENGTH LASER WITH THE VARIATION OF OPTICAL COUPLING RATIOS





This paper presents the characteristics of C+L band semiconductor optical amplifier based multi-wavelength laser with the variation of output optical coupling ratios. The configuration was tested with different coupling ratios from 10% to 90%. Meanwhile, the semiconductor optical amplifier injection currents varied from 110 mA to 340 mA in a step of 10 mA. The optimum coupling ratios were observed at 30%, 40%, 50% and 60% since it produces the maximum number of lasing lines, optical signal-to-noise ratio and average peak power. These coupling ratios also correspond to the minimum drive current of the semiconductor optical amplifier that initiates the first lasing lines. At 60% of the coupling ratio and injection current of 280 mA, the multi-wavelength laser has the capability to generate up to 42 dominant lasing lines with average peak power from -21 dBm to -35 dBm and an average optical signal-to-noise ratio from 9 dB to 11 dB. Furthermore, the minimum semiconductor optical amplifier current of 110 mA was required to initiate the first lasing at 60% of the coupling ratio. The semiconductor optical amplifier can effectively and practically act as a multi-wavelength source, especially in optical sensing and communication.



