MINOS

(Click for eps)

Graphs show percentage change in ADCs from before to after reflector connectors were fitted.
Left and right are 10m green fibre and 12m green fibre. Top is theoretical maximum (22%), next down is white paper reflector connector (4.38%), then aluminium foil connector (5.17%)and lastly aluminised mylar (6.76%).

Mylar is slightly translucent - an aluminised mylar connector with backing could be tried.