Impact of geometrical parameters on an oxide confined vertical cavity surface emitting laser with an integrated photonic crystal

Focused ion beam etching (FIB) was used to fabricate a two dimensional photonic crystal (PC)into the top distributed Bragg reflector (DBR) of an oxide-confined vertical-cavity surface-emitting laser (VCSEL) to create a PC-VCSEL. The influence of the geometrical parameters of the PC such as its lattice constant, the diameter and the depth of holes on the static and dynamic characteristics of the laser was investigated. It was shown that PC-VCSELs reduce transverse mode competition with single-mode radiation being observed an etching depth of 2.34 mum.The small signal modulation bandwidth was found to increase with the incorporation of PCs but is optimised for a shallower etching depth. Experimental results are analysed with various dynamical models of VCSELs with PCs.