Synthesis and characterization of transparent erbium–ytterbium co‐doped polymer nanocomposites for fabrication of polymer optical preform

Abstract

Synthesis of polystyrene (PS) and poly (methylmethacrylate) (PMMA)‐grafted Er–Yb co‐doped transparent ternary nanocomposite is presented herein. Er–Yb co‐doped nanoparticles (NP) were synthesized from their nitrate precursors followed by surface modification using 3‐methacryloxypropyltrimethoxysilane (MPS) as surfactant. In situ polymerization of methylmethacrylate (MMA) was performed in presence of benzoyl peroxide as initiator in toluene. The synthesized NP–PMMA composite was blended with PS in tetrahydrofuran (THF). Different material characterizations of synthesized composite were performed to evaluate shape, size and chemical nature of developed composite. UV–visible spectra and DLS technique revealed that optimum particle size in the range of <25 nm is essential to achieve optical transparency of developed composite. Refractive index of synthesized composite was also measured (RIcore > 1.5 at 589 nm) and indicate their potential application as active core material for preparation of rare earth doped polymer optical preform (POP). The POF preform prepared using commercially available cladding tube containing Er–Yb transparent polymer nanocomposites as core material is found to have numerical aperture around 0.19. The photoluminescence (PL) spectrum was also measured and intensity of Er–Yb co‐doped composite found to be ten times greater than pure Er‐doped system.