WLS study goals:
	SiPM coatings (high eficiency, optical clarity not important)
	coating for WLS/light guide bars for DM (high efficiency, optical clarity important
	
possible WLS materials:
	fluors
		TPB
		TPH+
	matrixes
		PEMA
			best sub 200nm tranmission - ref. suspect
		PS
			used by Conrad  10% seems low compared to Grande
		PMMA
			maybe best adhesion to acrylic?	
			is index matching important
		Teflon AF
			promises high sub 200 nm transmision
			high gas permeability - important?
	overcoats?
		MgF2
			for reduced outgassing - 
possible methods:
	solven evap
	dip - Dave likes this for large bars
	spray - Conrad
	spin coat

refs:
	Grande - TPH, TPB, various, TPH+secondary  in PEMA
	Lally - TPH vs TPB (evap) QE
	Eigen- PEMA transmission- orig ref.
	Conrad- TPB in PS
copies in:
 http://www-eng.lbl.gov/~shuman/NEXT/MATERIALS&COMPONENTS/WLS_materials/