Design of mixed HCG/DBR multilayer reflectors

We design a kind of mixed high-index-contrast subwavelength grating/distributed Bragg reflector (HCG/DBR) multilayer reflectors. The mixed HCG/DBR multilayer reflectors provide a broadband high reflectivity characteristic with several pairs which can replace conventional DBRs of InP-based materials. By applying the epitaxial lateral overgrowth (ELO), the design structure turns into a virtual InP substrate for growing InGaAsP/InP active regions without wafer bonding and it can be applied to some optical devices such as vertical-cavity surface-emitting lasers (VCSELs) and resonant cavity enhanced (RCE) photodetectors. Here some structure parameters (pairs, period and duty cycle) are optimized to achieve broadband high reflectivity by numerical simulations.