Low (Sub-1-Volt) Halfwave Voltage Polymeric Electro-optic Modulators Achieved by Controlling Chromophore Shape
Yongqiang Shi,
1
Cheng Zhang,
2
Hua Zhang,
3
James H. Bechtel,
1
Larry R. Dalton,
24
Bruce H. Robinson,
4
William H. Steier
3
Electro-optic (EO) modulators encode electrical signals onto fiber
optic transmissions. High drive voltages limit gain and noise levels.
Typical polymeric and lithium niobate modulators operate with halfwave
voltages of 5 volts. Sterically modified organic chromophores have been
used to reduce the attenuation of electric field poling-induced
electro-optic activity caused by strong intermolecular electrostatic
interactions. Such modified chromophores, incorporated into polymer
hosts, were used to fabricate EO modulators with halfwave voltages of
0.8 volts (at a telecommunications wavelength of 1318 nanometers) and
to achieve a halfwave voltage-interaction length product of 2.2 volt-centimeters. Optical push-pull poling and driving were also used
to reduce halfwave voltage. This study, together with recent
demonstrations of exceptional bandwidths (more than 110 gigahertz) and
ease of integration (with very large scale integration semiconductor
circuitry and ultra-low-loss passive optical circuitry) demonstrates
the potential of polymeric materials for next generation
telecommunications, information processing, and radio frequency
distribution.
1 TACAN Corporation, 2330 Faraday Avenue,
Carlsbad, CA 92008, USA.
2 Loker Hydrocarbon
Research Institute and Department of Chemistry, University of Southern
California, Los Angeles, CA 90089, USA.
3 Center for
Photonic Technologies, Department of Electrical Engineering, University
of Southern California, Los Angeles, CA 90089, USA.
4 Department of Chemistry, University of Washington,
Seattle, WA 98195, USA.