We show that a single-layer antireflection coating on a THz source of high refractive index can substantially increase the transmission of emitted THz pulses. Calculations indicate that the optimum coating thickness depends on the exact shape of the generated THz waveform and whether the transmitted waveform is to be optimized for the highest peak (temporal) amplitude, peak spectral amplitude, or pulse energy. We experimentally demonstrate a 15% increase in peak amplitude, a 33% increase in peak spectral amplitude, and a 48% increase in energy for a 100 μm thick fused silica AR coating on a lithium niobate crystal used as THz emitter.
© 2013 Optical Society of America
Original Manuscript: March 7, 2013
Revised Manuscript: April 25, 2013
Manuscript Accepted: April 27, 2013
Published: May 30, 2013
Fabian D. J. Brunner and Thomas Feurer, "Antireflection coatings optimized for single-cycle THz pulses," Appl. Opt. 52, 3829-3832 (2013)