Multilayer polymer mirrors

When desigtung a new product, a design team begins by specifying the desired optical properties. Then, it designs a stack of on the order of 100-1,000 layers of polymer films. Next, it designs extrusion devices to properly blend the polymer, and feed-block-splitters that divide the flow into 100-1,(K)0 thin films. The effluent films from these splitters are stacked at high extrusion speeds. 

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Weber M. F., Stover C. A., Gilbert L. R., Nevitt T. J., Ouderkirk A. J. Giant bire-fringent optics in multilayer polymer mirrors Science 287, 2451 (2000). 

Weber, MX., C.A. Stover, LX. Gilbert, T.J. Nevitt, and A.J. Oud-etkirk, Giant Birefiingent Optics in Multilayer Polymer Mirrors, Science, 287, Match 31 (2000). 

M. E Weber et al., Giant Bireffingent Optics in Multilayer Polymer Mirrors, ... 

Poly(polyethylene glycol-co-naphthalate), (I), was previously prepared by Hebrink et al. (2) and used in multilayered polymer films as a reflective polarizer or mirror. 

A difficulty arises because the photonic crystal structures for the visible region are not easy to fabricate. However, in this chapter we describe a facile extrusion method for fabricating polymers with a ID structure like that shown in Figure 2. The nanolayered polymeric structures can consist of many thousands of layers and have a modulation in the nonlinear refractive index in the direction normal to the surface of the layers. Such materials are the nonlinear analogue of polymeric multilayer interference mirrors. (10,11,12) They are also the ID analogue of the 2D photonic crystals studied by Lin et. al. (13) The latter workers demonstrated that photonic crystals do indeed provide an effective method for converting an intensity dependent refractive index into an intensity dependent transmission. 

Polymer materials find a wide application in replication technologies for producing structures with submicron elements of intricate shapes and for nano-scale surface replication [1-4]. They show considerable promise for smoothing out the surface roughness to obtain good-quality inexpensive substrates used in fabrication of X-ray optic components [5,6], In this work, the features of silicon wafer surface replication by polymers were studied by atomic-force microscopy (AFM) and X-ray reflectometry (XRR) with a view to applying this replication technique to produce smooth polymer-glass combination substrates to be used in multilayer X-ray mirrors. 

Composite materials are materials that consist of phases of dissimilar materials either in the form of layers or phases dispersed in a matrix. In many applications, multilayer film structures (layered composites) are used. Multilayer films having differing optical properties are used in forming AR coatings, heat mirrors, and band-pass filters on optical components. Multilayer thin films have many applications. The layers may be of different metals or may be a mixture of metals, oxides, and polymers. For example, a multilayer structure of polymer and oxide has been shown to have excellent moisture and oxygen permeation barrier properties. 

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