Numerical optimization of DFB LD grating structure for uniform longitudinal intensity distribution

We have developed a numerical optimization program that uses a region dependent grating structure and/or multi-phase shift DFB LDs with uniform longitudinal intensity distributions. The effectiveness of the program was confirmed by calculating longitudinal optical intensity distributions, and its effectiveness has been demonstrated for restricted tuning variables conditions. Since the restriction arising from our fabrication conditions is included in the optimization procedure, the obtained tuning parameters take into account the actual fabrication. It is concluded that an overall grating coupling coefficient design for high performance DFB LDs can be automatically achieved by using the current program.