Optimization of broadband semiconductor chirped mirrors with genetic algorithm

Genetic algorithm was applied for optimization of dispersion properties in semiconductor Bragg reflectors for applications in femtosecond lasers. Broadband, large negative group-delay dispersion was achieved in the optimized design: The group-delay dispersion (GDD) as large as −3500 fs2 was theoretically obtained over a 10-nm bandwidth. The designed structure was manufactured and tested, providing GDD −3320 fs2 over a 7-nm bandwidth. The mirror performance was verified in semiconductor structures grown with molecular beam epitaxy. The mirror was tested in a passively mode-locked Yb:KYW laser

Ultra-thin VCSELs based on monolithic subwavelength high-index contrast surface gratings

We present for the first time the measured power reflectance of GaAs monolithic high index contrast surface gratings (MHCGs) and computer simulations of various reduced-vertical-dimension VCSEL designs that employ these MHCG structures. We demonstrate the first optically-pumped MHCG DBR VCSELs with emission near 980 nm