Widely tunable lasers for wavelength-division multiplexed communications

Recently developed very wide tuning range semiconductor lasers have potential for use as sources in wavelength-division multiplexing (WDM) communications systems. The low-chirp and high-bandwidth modulation capabilities of sampled grating distributed Bragg reflector (DBR) lasers make them well suited for this application. SGDBR lasers have been fabricated with 62-nm cw tuning ranges, 5-MHz linewidths, and >40 dB mode suppression ratios. In this paper, we investigate the data transmission characteristics of directly modulated SGDBR lasers. The bit error rates were measured for both back-to-back and 50-km transmission on four separate wavelengths.