Microwave Characterization Of Electro-Optic Polymers
- PDF / 72,798 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 60 Downloads / 178 Views
B9.15.1
Microwave Characterization Of Electro-Optic Polymers Guru Subramanyam1, Prasanna Mathala1, Christine Chevalier2, Antonio Davis3, Perry Yaney4, and James Grote5 1 Department of Electrical &Computer Engg., University of Dayton, Dayton, OH 45469 2 Analex Corp., NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH 44135 3 Electro-Optics Graduate Program, University of Dayton, Dayton, OH 45469 4 Electro-Optics and Department of Physics, University of Dayton, Dayton, OH 45469 5 AFRL MLPS, Materials and Manufacturing Directorate, WPAFB, Dayton, OH 45432
ABSTRACT Electro-optic polymer thin-films were characterized at microwave frequencies, for possible applications in GHz modulators. Single layers of the polymers were spin coated on low loss magnesium oxide substrates for characterizing the polymers at microwave frequencies. Coplanar waveguide test structures were designed for evaluation of the relative dielectric permittivity as well as the loss-tangent of the polymers at microwave frequencies. A conformal mapping technique was used for the extraction of relative dielectric constant of the polymer films based on the microwave scattering parameter measurements. As an example, a DR1PMMA polymer had a relative dielectric permittivity of 3.01 and a loss-tangent of 0.075 at 8 GHz. The design of the test structures, the procedure for the accurate determination of the dielectric permittivity and the loss-tangent of the polymer films are discussed in this paper.
INTRODUCTION Photonics offers many advantages over conventional metallic lines and waveguides: lower weight, smaller size, larger bandwidth, and immunity to electromagnetic interference are a few of their advantages. Modulation rates in excess of 100 GHz have been demonstrated with nonlinear optical (NLO) polymer-based optoelectronic modulators. In addition, polymer-based optoelectronic devices have demonstrated resistance to high levels of radiation. Nonlinear optical polymers have boasted several attractive potential characteristics for optoelectronic modulator devices. Included are a high electro-optic coefficient for low voltage operation (emitter-coupled circuits required for GHz rates operate between -0.75 and -1.55 V), a low dielectric constant for high speed modulation, excellent index match to optical fibers for low loss coupling and a simplified fabrication process for lower cost[1-3]. Several NLO polymers have been developed and their optical as well as dielectric properties have been determined for use as a core as well as cladding layers [1-3]. The materials studied in this effort were Baytron P in PVA, which is a candidate polymer for a conductive cladding, and host polymer poly(methyl methacrylate), PMMA, doped with chromophore dispersed red 1, DR1, which is a typical of a poleable polymer suitable for the nonlinear optical core material in a electro-optical polymer modulator. These materials were chosen to provide a database for modeling studies of GHz modulator structures. This manuscript details the microwave characterization of thes
Data Loading...
