Distributed feedback semiconductor laser device multiplexer channel analog optic fiber communications system

摘要

PURPOSE: To provide a grating dispersed feedback laser having accurately controlled κL value. ;CONSTITUTION: A DFB semiconductor laser is improved. In particular, this laser has a modal decay length t₀ with parameter α, the multilayered structure of a semiconductor element is composed of a planar active layer 13, diffraction lattice layer 15 which is approximately parallel to the active layer 13 and spacer layer 14, having a thickness t_s between the layers 13, 15 where t_s is within ±10% of t₀/(1-α). The spacer layer thickness is adequately selected to make invariant the κL value of at least a certain type of DFB lasers against inevitable variation in the manufacturing conditions, resulting in an elevated product yield.;COPYRIGHT: (C)1995,JPO