Studies on the preparation of gradient‐index polymeric rods by interfacial‐gel copolymerization

Preparation of large‐sized graded‐index polymer preform

“…Yang et al 9 found that increasing the concentration of initiator from 0.5 to 1.0 wt %, and the increasing the chain-transfer agent from 0 to 1000 ppm could reduce the defect of GI polymer preform because of reducing the shrinkage of the polymers through decreasing the molecules weights of the prepared polymer. However, increasing the concentration of initiator or chain transfer would lead to increasing the impurity and optical attenuation of the GI polymer rods.…”

New insight into isothermal frontal polymerization models: Wiener's method to determine the diffusion coefficients for high molecular-weight poly(methyl methacrylate) with neat methyl methacrylate

“…One hindrance to these models is the lack of information in the literature on diffusion coefficients for the components used in IFP. (Much of the published experimental work on IFP used the monomer methyl methacrylate (MMA) with a high molecular-weight poly(methyl methacrylate) (PMMA) seed or used MMA derivatives [12,[15][16][17][18]20,23,[28][29][30].) Because diffusion coefficients for the exact system were not available, the mathematical models used published diffusion coefficients for low molecular-weight PMMA systems solvated by other solvents (e.g.…”

“…To produce IFP GRINs, which have been used as waveguides, laser applications, and other optical applications, a dopant (a second monomer or other material, e.g. a dye) can be added to the monomer solution [12,[14][15][16][17][18][19][20]. Spade et al discuss the mechanism to include the dopant, and all material in the subsequent sentences are from Ref.…”

Theoretical Analysis on a Multilayer Coextrusion Process for Preparing Gradient-Index Polymer Optical Fibers

“…Gradient-index (GI) polymer optical fibers (POFs) have attracted extensive interest in light of their versatile applications in optical communication, imaging, and collimating. − A GI POF based on perfluorinated (PF) polymer with an optical loss of 50 dB/km and a transmission speed of 2.5 Gb/s at 1.3 mm was prepared by Koike et al recently . It was reported that the theoretical attenuation limit of PF GI POF can be as low as 0.3 dB/km, which is comparable to that of a silica fiber in the near-infrared region.…”

“…The importance of GI POF stimulates several methods for preparing GI POFs. These include, for example, two-stage copolymerization, photocopolymerization, centrifugal molding, , interfacial gel copolymerization, ,,, and a coextrusion process. ,,, The differences between the monomer concentration, monomer reactivity, monomer size, monomer density, monomer diffusivity, the properties of the host polymers, and external process design are the basic design parameters for the production of an index gradient inside a fiber.…”