Here is an image of a 1x64 fiber optic splitter/combiner:
I am assuming these are plastic/polymer fibers. A very similar box (http://www.ebay.co.uk/itm/SC-UPC-1x32-Fiber-Optic-Splitter-PLC-Splitter-Module-SM-1M-Please-see-Options-/141150409820?hash=item20dd38545c:g:ao0AAOSwr81UOap3) permits 300mW of max optical power. Does this power rating seem reasonable and why?