The main objective of this project is precise analysis and explanation of physical phenomena limiting the performance characteristics and hampering the development of antimonide-based vertical-cavity surface-emitting lasers (VCSELs) designed for emission in the mid-infrared wavelength range. The proposed research will allow not only a better understanding of fundamental physical phenomena (electrical, thermal, optical and recombination) taking place within the VCSEL volume but will also permit to examine the complex interactions occurring between them. The proposed research aims will allow to formulate both design and material solutions which will not only contribute to the performance characteristics improvement (i.e. higher operating temperatures, higher output powers) of the reported VCSELs with emission wavelength up to 2.63 μm, but also to enable fabrication of VCSEL operating near 3 μm (or longer). Considering the fact that up to now there are only a few publications related to this issue, in addition with a lot of simplifications, the research proposed in this project will be, to the best of our knowledge, the first complex analysis of the mid-infrared antimonide-based VCSELs.