Wide-bandwidth and high-power InGaAsP distributed feedback lasers

Abstract
The fabrication and performance characteristics of a wide-bandwidth InGaAsP laser diode structure are described. The wide bandwidth is achieved using semi-insulating Fe-doped InP current blocking layers around the active region. The lasers have a bandwidth of 18 GHz at 20 mW, emit 50 mW in a single transverse and longitudinal mode, have rise and fall times of less than 40 ps, have low chirp (FWHM<1 Å) under modulation, and exhibit harmonic distortion characteristics in agreement with fundamental calculations using a rate equation model. Error-free transmission with no dispersion penalty has been obtained using these lasers in a transmission experiment at 8 Gb/s over 76 km of fiber.