Wavelength tunable semiconductor lasers for optical fiber communications

Recent progress in the area of wavelength tunable semiconductor lasers for advanced optical fiber communications is reviewed. The tuning characteristics are described, and applications for multiwavelength packet switching in photonic networks are presented. Simultaneous wavelength switching and data modulation up to 20 ASK (amplitude shift keying) wavelength channels and 48 FSK (frequency shift keying) wavelength channels at 200 Mb/s for each channel are possible with a three-sectioned tunable DBR (distributed Bragg reflector) laser having a continuous tuning range of 2.2 nm (290 GHz). The switching speed from one wavelength to another was only a few nanoseconds.<
>