Document nmYna3BQ1d8gQ5rRaMKmQ2g4m

Ref. 4 - Additional data on Polymer Optical Fibers (POFs) from Mitsubishi Chemical Potential alternatives to fluorinated polymers as cladding for POFs (relevant to derogated uses, potentially derogated uses and missing uses PMMA is used as a core material for POFs because it can be manufactured with sufficient purity and transparency to transmit light for long distances, has minimal birefringence and can be formed to a flexible fiber with sufficient strength. An important property of plastic optical fibres (POF) is the maximum coupling efficiency with the light source LED. The higher the maximum coupling efficiency, the more light power can be transmitted. The maximum efficiency is determined by the difference between the squared refractive indices of the core and cladding of the POF (ncore2-ncladd2). The lower the refractive index of the cladding, the greater the maximum coupling efficiency and the more effectively the light power from the source can be used. Table 1 and the figure below show the values of the refractive indices of various fluoropolymers (including fluorinated methacrylate), silicone resin and PMMA, and the theoretically calculated maximum coupling efficiency of POF when each is used as cladding. POFs with a maximum coupling efficiency of 25 % or higher are generally required, which is why cladding materials with a refractive index below about 1.4 are used. For reference, Tables 2 and 3 give a broader overview of refractive indices of polymeric materials. Table 1: Refractive indices of various resins and maximum bonding efficiency of POF when those resins are used as cladding* Chemical Substances Abbreviat ion PFAS PFAS PFAS PFAS PFAS Silicone Silicone PFAS PMMA Cytop (AGC) Fluorinated Ethylene Propylene Poly(tetrafluoroethylene) Cytop FEP PTFE Tetrafluoroethylene hexafluoropropylene THV vinylidene fluoride Poly(2,2,3,3,4,4,4-heptafluorobutyl 7FM methacrylate) Poly(methyl hydro siloxane)** dimethylpolysiloxane Poly(vinylidene difluoride) Poly(menthyl methacrylate) PMHS (liquid) PDMS PVDF PMMA Refractive Index of Cladding 1,31 1,338 1,35 1,35 Maximum Coupling Efficiency (%) 51,0 43,6 40,4 40,4 1,383 31,3 1,397 27,4 1,41 23,8 1,42 21,0 1,492 0,0 *The PFAS substances listed in Table 1 have been selected to illustrate the effect of the refractive index on coupling efficiency. For more refractive indices, see Table 3. **Cannot be used as cladding because it is liquid. Maximum Coupling Efficiency (%) Maximum coupling efficiency of POF and LED 60 50 Cytop FEP 40 PTFE 7FM 30 PMHS (liquid) PDMS 20 PVDF 10 0 1,3 PMMA 1,32 1,34 1,36 1,38 1,4 1,42 1,44 1,46 1,48 1,5 Refractive Index of Cladding Table 2: Refractive Indices of Some Conventional Polymers from https://omnexus.specialchem.com/tech-library/article/low-ultra-low-refractive- index-polymers Classified by polymer type Ascending ranking Commodity Engineering PE PP PVC PS UP PUR PA PET Acrylics PC POM 1.51-1.54 1.5-1.51 1.53-1.55 1.55-1.59 1.52-1.54 1.5-1.6 1.53-1.54 1.55-1.64 1.49-1.57 1.58-1.6 1.48-1.51 Fluorinated Epoxy POM Acrylics PP PUR PE UP PA PVC PS 1.31-1.4 1.45-1.6 1.48-1.51 1.49-1.57 1.5-1.51 1.5-1.6 1.51-1.54 1.52-1.54 1.53-1.54 1.53-1.55 1.55-1.59 Specialty PEI Sulfone Epoxy Fluorinated PEEK 1.66-1.67 1.63-1.65 1.45-1.6 1.34-1.4 1.65-1.77 PET PC Sulfone PEEK PEI 1.55-1.64 1.58-1.6 1.63-1.65 1.65-1.77 1.66-1.67 Note: The polymers PE, PP, PA, PET, POM and PEEK are not amorphous and thus not transparent Table 3: Low Refractive Indices of Numerous Fluoropolymers and a Few Non-fluorinated Polymers After: https://omnexus.specialchem.com/tech-library/article/low-ultra-low-refractive-indexpolymers Fluoropolymers Refractive indices TeflonTM AF (DuPont Spin-off - Now Chemours) 1.31+ Cytop (AGC) 1.31+ Poly(hexafluoropropylene oxide) 1.31+ Fluorinated Ethylene Propylene 1.338 Poly(tetrafluoroethylene-co-hexafluoropropylene) 1.338 Poly(pentadecafluorooctyl acrylate) 1.339 Perfluoroalkoxy 1.34 Poly(tetrafluoro-3-(heptafluoropropoxy)propyl acrylate) 1.346 Poly(tetrafluoro-3-(pentafluoroethoxy)propyl acrylate) 1.348 Poly(tetrafluoroethylene) 1.35 Tetrafluoroethylene hexafluoropropylene vinylidene fluoride 1.35 Poly(undecafluorohexyl acrylate) 1.356 Poly(nonafluoropentyl acrylate) 1.36 Poly(tetrafluoro-3-(trifluoromethoxy)propyl acrylate) 1.36 Poly(pentafluorovinyl propionate) 1.364 Poly(heptafluorobutyl acrylate) 1.371 Poly(trifluorovinyl acetate) 1.375 Poly(1,1,1,3,3,3-hexafluoroisopropyl acrylate) 1.375 Poly(octafluoropentyl acrylate) 1.38 Poly(methyl 3,3,3-trifluoropropyl siloxane) 1.383 Poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) 1.383 Poly(pentafluoropropyl acrylate) 1.385 Poly(2,2,3,3,3-pentafluoropropyl acrylate) 1.389 Poly(2-heptafluorobutoxy)ethyl acrylate) 1.39 Poly(chlorotrifluoroethylene) 1.39 Poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate) 1.39 Poly(2,2,3,4,4-hexafluorobutyl acrylate) 1.392 Poly(2,2,3,4,4,4-hexafluorobutyl acrylate) 1.394 Poly(2,2,3,3,3-pentafluoropropyl methacrylate) 1.395 Non-fluorinated polymers Refractive indices Poly(methyl hydro siloxane) 1.397 Hydroxypropyl cellulose 1.337 Dimethylpolysiloxane 1.41 Poly(vinylidene difluoride) 1.42 Liquid When dissolved in a solvent.