This component enables flash photolysis and fluorescence illumination to be performed simultaneously through a microscope episcopic port. It comprises of two light guide inputs at 90 degrees with a dichroic mirror to allow different sections of the spectrum to be combined. Typically we would fit a 400nm long-pass dichroic mirror to allow photolysis <400nm and fluorescence > 400nm. After combination the light is either collimated and the focussed, or focussed directly depending on the type of microscope.