Curable compositions include an acrylate of Formula I: Formula I at least one multifunctional (meth)acrylate with fused aromatic groups, heteroarylene groups, heteroalkylene groups, alkylene groups, or aralkylene groups, and a photoinitiator. The compositions, when cured, have a refractive index of 1.63 or greater at 532 nanometers, are optically transparent, and have a thermal stability such that upon heating for 1 hour at 250° C. they have a weight loss of 3.5% or less.