Theory for optimum design and analysis of distributed-feedback lasers

Theory for optimum design of a distributed-feedback (DFB) laser is presente d, based on a new set of coupled-power equations, A novel lambda/4 phase sh ift index-coupled AR-coated DFB laser structure, which theoretically exhibi ts a longitudinally uniform power density, is proposed. It is shown that th e theory is very simple and provides an easy way to analytically understand the physical mechanism crucial for the optimum design. Our theory can also be easily applied to the optimization of the design of gain-coupled, compl ex-coupled DFB laser structures as well as high power DFB lasers.