Electrooptic polymers for wideband THzapplications

1
Electro-optic polymers for wideband
THz-applications Alexander Sinyukov, Peter
Lindahl, Joey French, and L. Michael Hayden,
Department of Physics, University of Maryland,
Baltimore County, Baltimore, MD 21250 Meng He and
Robert J. Twieg, Department of Chemistry, Kent
State University, Kent, OH 44242
Materials
Optical rectification
EO polymer properties

• ?high electro-optic coefficient (r33 50 pm/V _at_
  785 nm)
• ??no phonon absorption !!
• ??phase matching ??
• ??n 1.75 _at_ 800 nm,?static dielectric constant,
  e 3
• ??50-500 mm thick
• ??????????versatility
• cheap !

Electro-optic polymer composites are fabricated
from mixtures of nonlinear optical chromophore
guests and polymer hosts (PMMA, APC).
Lemke-e m 8.31 Debye, ? 12165 esu
Wideband, sub-ps visible light generates far-IR
femtosecond pulses via three wave mixing amongst
the input frequencies.
Electro-optic detection
Predicted frequency response
DCDHF-MOE-V m 12.3 Debye, ? 18576 esu. mb/M
1.9 x Lemke

• phonon absorption gaps in ZnTe, GaP response
• ? very thin crystals required for wideband
  response
• ? no resonances in polymer composites
• ? coherence length tuning possible in polymers
• ? polymers have larger response (rpolymer gt
  rcrystal)

13 mm thick scaling
DCDHF-6-V m 12.7 Debye, ? 18640 esu m?/M
1.7 x Lemke
The THz beam provides the electric field which
modulates the index of refraction in the c(2)
material. Balanced detection increases the
signal-to-noise ratio.
Wideband emission
THz-performance of EO polymer
Experimental setup