title: Gradient-index materials based on thiol-ene networks.
abstract: Gradient-index (GRIN) optics offer spatially varied refractive indexes that can enhance current imaging technologies. Current methods to fabricate GRIN optics are highly complex and costly. Here we report a simple and efficient method that utilizes commercially available reagents to fabricate polymeric GRIN optics with significant refractive index differences (Δn = 0.04). First, two different mixtures of network precursors are layered and time allotted for molecular diffusion in the liquid state, prior to curing. The resulting, partially mixed layers are UV-cured to yield clear, glassy molecular networks with fixed refractive index gradients. The fully cured network resins exhibit smoothly varying composition and refractive index over centimeter length scales, confirmed by spectroscopy and interferometry.
authors: †250 Gavett Hall, Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, United States.
authors: Yuan
authors: Y
authors: Meng
authors: †250 Gavett Hall, Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, United States.
authors: Molly
authors: M
authors: Tsai
authors: ‡275 Wilmot Building, The Institute of Optics, University of Rochester, Rochester, New York 14627, United States.
authors: Greg R
authors: GR
authors: Schmidt
authors: †250 Gavett Hall, Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, United States.
authors: Mitchell
authors: M
authors: Anthamatten
keywords: controlled diffusion; gradient materials; photopolymerization; thiol−ene click reaction