The proliferation of optical systems has manifested the need for materials that possess a unique combination of physical, chemical, and optical properties as well as being easily fabricated into low loss waveguide structures. This paper focuses on the optical properties and waveguide performance of perfluorocyclobutyl-based (PFCB) polymers and copolymers. Topics include their experimental and theoretical optical performance, new PFCB derivatives and hybrids, and novel highly light emissive nanocomposites using inorganic lanthanide nanoparticles.
Fluoropolymers are viable material options for short haul fiber and planar waveguide photonic applications. This work provides the refractive index, extinction coefficient, Sellmeier coefficients, and infrared absorption for two perfluorocyclobutyl-based (PFCB) polymers. These PFCB fluoropolymers have marked themselves as alternatives to the more well known fluoropolymers based on their solution processability and broad tailorability of optical, thermal, and mechanical properties.
Perfluorocyclobutyl (PFCB) polymers and copolymers have a unique combination of properties well suited for optical applications such as high temperature stability, precisely controlled refractive index, low moisture absorption, excellent melt and solution processability, a variable thermo-optic coefficient, and low transmission loss at 1300 and 1550 nm. Electro-optical devices from polymers of ring locked polyene chromophores are attractive due to their thermal, mechanical, optical and dielectric properties. Polyene chromophores with highest hyperpolarizability are covalently attached to trifluorovinyl aryl ether containing moieties and copolymerized with other monomers. The resulting polymers display imrpoved thermal stability, solubility and good film forming capabilities.
Bis-ortho-Diynyl Arene (BODA) monomers polymerize to network polynapthalene by the thermally-driven Bergman cyclization and subsequent radical polymerization via oligomeric intermediates that can be melt or solution processed. Further heating of the network to 1000 °C affords a high-yield glassy carbon structure that retains the approximate size and dimensions of the polymer precursor. The higher carbon-yield for BODA networks (75- 80 % by mass) is significantly greater than that of traditional phenol-formaldehyde resins and other carbon precursor polymers leading to its greater dimensional stability. Phenyl terminated BODA derived polymers were fabricated using microprocessing such as the micromolding in capillaries (MIMIC) technique, direct microtransfer molding, and molding in quartz capillary tubes. Nano-scale fabrication using closed packed silica spheres as templates was demonstrated with an hydroxy-terminated monomer which exhibits greatly enhanced compatibility for silica surfaces. After pyrolysis to glassy carbon, the silica is chemically etched leaving an inverse carbon opal photonic crystal which is electrically conductive. The wavelength of light diffracted is a function of the average refractive index of the carbon/ filler composite, which can be modified for use as sensitive detector elements.
Perfluorocyclobutyl (PFCB) polymers and copolymers enjoy a unique combination of properties well suited for optical applications such as high temperature stability, precisely controlled refractive index, low moisture absorption, excellent melt and solution processability, a variable thermoptic coefficient, and low transmission loss at 1300 and 1550 nm. Copolymerization reactions offer tailored thermal and optical properties by simple choice of comonomer. PFCB copolymers can be solution or melt microfabricated via standard methods and can also be processed via micro-transfer molding in photolithographically generated features. Reliable molding of polymer waveguides offers significant potential to reduce photonic integrated circuit (PIC) fabrication costs and enable the realization of compact, integrated subsystems for a variety of applications. Copolymerization chemistry, thermoptic measurements, and initial results on the first micro-transfer molded waveguide structures are presented.
Polymeric materials, in both fiber and planar form, are finding increasing application in commercial optical communication systems. This paper compares and discusses the intrinsic optical properties of common organic materials used in polymer waveguides as relates to their expected performance in optical fibers and rare earth amplifiers. Specifically considered and compared are polymethyl methacrylate (PMMA), Teflon-AF, Cytop, and perfluorocyclobutyl (PFCB) polymers.
Organic polymers are increasingly attractive alternatives to inorganic materials in telecommunication devices. Polymers offer flexibility, low cost fabrication and connection, high transparency in the visible and near-infrared spectra, and versatility in structure, properties, and grades for task specific integration such as local-area-network applications. Halogenated polymers in particular show negligible transmission losses in the range desired and fluoropolymers represent the lowest loss examples of organic polymers to date. However, commercial perfluoropolymers in general are limited by poor processability, non-trivial refractive index matching, and they typically do not exhibit the thermal and thermomechanical stability required for some commercial processes and extreme environment in-use applications. Our strategy has focused on the thermal cyclopolymerization of trifunctional and bifunctional aryl trifluorovinyl ether monomers to perfluorocyclobutane (PFCB) copolymers. PFCB polymers and copolymers enjoy a unique combination of properties well suited for optical applications such as high temperature stability, precisely controlled refractive index, low moisture absorption, excellent melt and solution processability, a high thermooptic coefficient, and low transmission loss at 1300 and 1550 nm. Copolymerization reactions offer tailored thermal and optical properties by simple choice of comonomer. PFCB polymers can be solution or melt microfabricated via standard methods and can also be processed by soft-lithography techniques. Polymerization and processing parameters and characterization including thermal properties (Tg = 120-350 degree(s)C), optical loss (< 0.2 db/cm at 1550 nm), refractive index tunability (1.449-1.508 at 1550 nm), low birefringence, and optical stability is presented.