Transient Chirp Suppression in Directly Modulated Microring Lasers

The effect of internal feedback through bus waveguide reflectivity has been numerically evaluated as a key parameter for the improvement of direct modulation properties of microring lasers. According to calculations, appropriate values of feedback power result in damped relaxation oscillations and consequent transient chirp reduction. An evaluation of the above technique at 10 Gb/s including fiber transmission over 10 and 20 km indicates that microring lasers could efficiently operate as low-cost directly modulated transmitters in metro/access networks.