Distributed feedback lasers with temperature tuning over 4.5 nm for WDM 2.5-Gbit/s, 300-km, transmission

Summary form only given. To address the rapid growth of the wavelength-division multiplexing (WDM) market, optical sources that can be tuned over several channels width must be developed. A simple solution is provided by temperature tuning of a directly modulated laser. Although attractive, this is technically unfeasible unless the laser chirp characteristics can be minimized over a large range of temperature. We report here on Henry factor and adiabatic chirp measurements between 25-85 C for several laser types. Following these results, wavelength tuning over several nanometers was demonstrated on an optimized structure for 300- and 360-km-long transmission on conventional optical fiber at a rate of 2.5 Gbit/s by changing the temperature over 50 C. The devices under tests were 300-/spl mu/m-long buried ridge structure (BRS) distributed feedback (DFB) lasers emitting at 1.55 /spl mu/m. The amplitude and frequency modulation characteristics were measured with a Mach-Zender interferometer.