Hey that's a nice effect ! Maybe look into using the "mix material node" with a " polygon side " node as switch input . That way you can use a opaque front side material and a self illuminating( emissive ) back side with transparency for the pattern you've created .

that's no really work, this FX ...

I use the specular SOP to make a Backlight Light FX in mantra, may I know how can I do the same FX in Octane