LAPAREX - An automatic parameter extraction program for gain- and index-coupled distributed feedback semiconductor lasers, and its application to observation of changing coupling coefficients with currents

A reliable and automatic parameter extraction technique for DFB lasers is d eveloped. The parameter extraction program which is named "LAPAREX" is able to determine many device parameters from a measured sub-threshold spectrum only, including gain- and index-coupling coefficients, and spatial phases of the grating at front and rear facets. Injection current dependence of co upling coefficients in a gain-coupled DFBlaser is observed, for the first t ime, by making use of it.