Abstract: The present invention relates to novel photoresist compositions and processes for preparing the same utilizing polymers having a low polydispersity via the use of certain chain transfer agents (CTA) with certain monomers to provide said polymers. The polymers incorporating the chain transfer agents can be homopolymers, or made with additional monomers to provide copolymers. These polymers/copolymers are then converted into photoresist compositions for use as such.

Abstract: Polymers derived from various monomers are purified by fractionalization of the crude polymers in a solvent/non solvent system via reverse precipitation.

Abstract: An anhydrous, liquid phase process for preparing hydroxyl containing polymers of enhanced purity comprising the steps of polymerization, purification, transesterification, purification, catalyst removal, and solvent exchange. The resultant polymer in solution can be used directly, without further processing steps, to prepare a photoresist composition.

Abstract: In one embodiment this invention provides a frequency doubling optical waveguide consisting of a substrate-supported polymeric thin film waveguiding layer, in combination with one or more polymeric cladding layers. The waveguiding layer comprises moieties which exhibit nonlinear optical properties as well as anomalous dispersion of refractive index such that, under wave propagating conditions, the effective dispersion .DELTA.N of the waveguiding layer is zero, and the fundamental and second harmonic waves are phase matched over the length of the waveguide.