A Widely Tunable Directly Modulated DBR Laser With High Linearity

We demonstrate a widely tunable and high-modulation-bandwidth distributed Bragg reflector (DBR) laser. With the selected butt-joint material (λg = 1.44 μm) and butt-joint angle (45°) for the grating section, a widely tuning range of 13.88 nm with 19 consecutive channels is obtained for the two-section DBR laser. Furthermore, a small-signal modulation bandwidth of 16 GHz with in-band flatness of ±3 dB is realized at 10 °C. A uniform modulation bandwidth of more than 13 GHz is obtained for ten consecutive channels at 25 °C. Meanwhile, the DBR laser shows a high linearity, with an input 1-dB compression point of 17 dBm and an input third-order intercept point of 30 dBm at 13 GHz.