Wavelength-controlled DFB LDs for WDM systems

Wavelength division multiplexed (WDM) lightwave systems are expected to use many wavelength-controlled light sources. The simultaneous fabrication of different wavelength laser diodes (LDs) on a wafer is therefore an important technology which would allow WDM light sources to be prepared at low cost. The lasing wavelengths of these LDs must be precisely controlled to coincide with pre-assigned wavelength grids for WDM systems. Each LD with different wavelength should have uniform lasing characteristics. We developed a new type of wavelength controlled distributed feedback (DFB) LD. Uniform lasing characteristics were demonstrated for 40-channel different wavelength DFB LDs fabricated on one wafer, over a 75 nm-wide wavelength range.