1. Introduction . Since VCSELs have many unique features, they have solidified their status as a major active device in microwave photonic links, short-distance optical interconnections, laser radar and chip-scale atomic clocks [ 1 – 5 ]. Meanwhile, gigabit Ethernet and fiber channel applications are driving the current VCSEL market [ 6 – 10 ]. However, one of the challenging issues in VCSEL reliability is their sensitivity to ESD [ 11 , 12 ]. There is still a critical issue...