Marine-based deoxyribonucleic acid (DNA), purified from waste products of the Japanese fishing industry, has recently become a material of interest in photonics applications. Using highly purified DNA, unique processing techniques developed specifically to transform the purified DNA into a biopolymer suitable for optical device fabrication are reported.

Our research in nonlinear optic (NLO) polymer-based electro-optic (EO) modulators has centered on optimizing device performance through the using of polymer cladding layers with higher relative conductivities than the NLO core material. We have demonstrated as much as a 10 times increase in the effective EO coefficient of electrode poled, guest/host NLO polymers, compared to using passive polymer claddings. We have achieved the lowest poling voltage to date for maximum EO coefficient, 300 V, for a two-layer waveguide structure consisting of a 2 µm thick NLO polymer layer and 2 µm thick conductive cladding layer. Optimized polymer cladding materials posessing the desired optical and electromagnetic properties we find need to be balanced with materials processability. In addition to the conventional polymer materials under investigation, a novel material, deoxyribonucleic acid (DNA), derived from salmon sperm, has shown promise in providing both the desired optical and electromagnetic properties, as well as the desired resistance to various solvents used for NLO polymer device fabrication. Our investigation also includes intercalation of fluorescent dyes, photochromic dyes, nonlinear optic chromophores, two-photon dyes, and rare earth compounds into a DNAbased host material and comparing results with poly(methyl methacrylate) (PMMA)-based host materials.

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An electro-optic (EO) planar waveguide modulator using a deoxyribonucleic acid (DNA)-based biopolymer for both the waveguide core and cladding layers has been fabricated and its performance evaluated. A cross-linked DNA-surfactant biopolymer was used for the top and bottom cladding layers and the core layer was a cross-linked DNA-surfactant biopolymer with 3wt% Disperse Red 1. The EO coefficient r33 was induced through contact poling. The fabricated device was found to exhibit EO modulating behavior. Using an estimated value of r33=0.5pm∕V, a sine-squared fit to the modulating data was obtained with Vπ=263V±10%.

A laser-based technique for accurate measurement of the population density profiles of the 2 3 S 1 helium metastable in a parallel-plate, glow discharge is described. The system utilizes a distributed-Bragg-reflector diode laser operating at 1083 nm to perform absorption measurements on the 2 3 S 1 → 2 3 P J transitions of helium. The narrow bandwidth (<3 MHz) of the laser permits simultaneous measurement of the line-integrated metastable density and gas temperature. Axial and radial distributions of the triplet line-integrated metastable density were measured in normal and abnormal glow discharges. Current densities ranging from 8 µA cm −2 (normal glow) to 175 µA cm −2 (abnormal glow) were used at static gas pressures of 2 and 5 Torr. Abel inversion of the data provided a spatial distribution of the 2 3 S 1 metastable density that shows a region that has near one-dimensional character. The location of the peak triplet metastable density in the plasma was displaced from the peak of the negative glow emission towards the anode. Axial profiles of triplet metastable density gave values from 5 × 10 9 to 1.2 × 10 11 cm −3 for current densities of 8 to 175 µA cm −2 , respectively.

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