Bandwidth enhancement of injection-locked distributed reflector lasers with wirelike active regions

The modulation bandwidth enhancement of distributed reflector (DR) lasers with wirelike active regions utilizing optical injection locking is demonstrated both theoretically and experimentally. By the rate equation analysis, it is shown that DR lasers with wirelike active regions realize a low optical injection power and a large bandwidth enhancement under small operation currents. Experimentally, the small-signal bandwidth is increased to >15 GHz at a bias current of 5 mA, which is 4 times smaller than that for conventional edge-emitting lasers. A large signal modulation at 10 Gbps is also performed at the same bias current of 5 mA and voltage swing of 0.4 V(pp), and error-free detection was confirmed under the low-power conditions.