Narrow linewidth 1.55μm directly modulated distributed-feedback laser

Abstract

We fabricated a narrow linewidth 1.55μm directly-modulated distributed-feedback (DFB) laser. The laser exhibits an output power of 14mW at 100mA, flat frequency response with -3 dB bandwidth of 18 GHz, the third-order intermodulation distortion (IMD3) with 39.8dBm, narrow optical linewidth with 181kHz, and RIN below -135.7dB/Hz in the 0.1-10GHz range along with the high side-mode suppression ratio (<52dB). We also experimentally verified the modulation bandwidth, linearity, and linewidth is related to the bias current. The characteristics of the laser, namely sufficient modulation bandwidth, high linearity, low relative intensity noise (RIN) and narrow linewidth, make it the perfect candidates for high dynamic directly modulated analog optical link.