Low-chirp highly linear 1.55 mu m strained-layer MQW DFB lasers for optical analog TV distribution systems

The design and realization of highly linear 1.5- mu m distributed-feedback (DFB) lasers for optical analog TV distribution systems based on dispersive single-mode fibers are reported. A simple and comprehensive model relating grating characteristics to laser chirp was developed and used for optimization of the DFB grating. The model predicts that lasers emitting at wavelengths located in the positive slope sections of the DFB-reflectivity-wavelength characteristic have higher resonance frequencies and reduced chirp. The lasers were realized by using strained-layer multiple quantum wells for high differential gain and low alpha factor, antireflection (AR) coating of one laser facet for reduction of internal photon density, and a special grating design for low spatial hole burning and chirp reduction. >