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 = nm)
no phonon absorption !!
phase matching ??
n = 800 nm,static dielectric constant, e ~ 3
 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,  = esu.
mb/M = 1.9 x Lemke
THz beam
pellicle
polarizer
compensator
c(2) material
polymer
[110]
ZnTe
[1-10]
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 > rcrystal)
13 mm thick scaling
DCDHF-6-V
m = 12.7 Debye,  = 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
film
ITO
glass
1 cm
THz-performance of EO polymer
Experimental setup