Interesting use for VCSEL.
"By improving the heat dissipation of the overall module, it can now deliver the high energy output needed by the laser crystal light source in a laser ignition plug head. This type of plug head has been attracting attention as a means of igniting gas engines for power generation used in cogeneration systems and other equipment."
http://www.semiconductor-today.com/news_items/2016/jul/ricoh_060716.shtml