Three methods for distortion-free enhancement of electro-optic sampling measurements of terahertz signals are tested. In the first part of this two-paper series [J. Opt. Soc. Am B 31, 904–910 (2014)], the theoretical framework for describing the signal enhancement was presented and discussed. As the applied optical bias is decreased, individual signal traces become enhanced but distorted. Here we experimentally show that nonlinear signal components that distort the terahertz electric field measurement can be removed by subtracting traces recorded with opposite optical bias values. In all three methods tested, we observe up to an order of magnitude increase in distortion-free signal enhancement, in agreement with the theory, making possible measurements of small terahertz-induced transient birefringence signals with increased signal-to-noise ratio.
© 2014 Optical Society of America
Original Manuscript: January 16, 2014
Manuscript Accepted: March 1, 2014
Published: April 8, 2014
Jeremy A. Johnson, Fabian D. J. Brunner, Sebastian Grübel, Andrés Ferrer, Steven L. Johnson, and Thomas Feurer, "Distortion-free enhancement of terahertz signals measured by electro-optic sampling. II. Experiment," J. Opt. Soc. Am. B 31, 1035-1040 (2014)