Abstract-Broadband antireflection coating for optimized terahertz beam splitters

Weien Lai, Norman Born, Lorenz Maximilian Schneider, Arash Rahimi-Iman, Jan C. Balzer, and Martin Koch
https://www.osapublishing.org/ome/abstract.cfm?uri=ome-5-12-2812

We investigate the potential of anti-ferromagnetic nanofilms as broadband antireflection coatings in the terahertz frequency range. The anti-ferromagnetic layer is modeled by an analytic wave-impedance matching approach. The experimental results of the transmission and reflection measurements demonstrate the effectiveness of our antireflection coatings. Furthermore, we use anti-ferromagnetic nanofilms as antireflection coating for a terahertz beam splitter. Compared with conventional terahertz beam splitters consisting of an uncoated thick silicon wafer, the coated silicon beam splitter has two advantages: elimination of multiple reflections and improvement of the signal-to-noise ratio for terahertz time-domain spectroscopy in reflection geometry.

© 2015 Optical Society of America

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Abstract-Interferometric Characterization of a Semiconductor Disk Laser driven Terahertz Source

Matthias Wichmann, 

Markus Stein, 

Arash Rahimi-Iman, 

Stephan W. Koch, 

Martin Koch

http://link.springer.com/article/10.1007%2Fs10762-014-0069-9

Michelson interferometry is used to investigate the pump-power dependent emission bandwidth of a THz emitter based on intra-cavity difference frequency generation in a two-color VECSEL. A multi-mode CW THz signal is found to result from the two simultaneously lasing groups of longitudinal VECSEL modes. Power-dependent experiments reveal a clear correlation between the THz signal bandwidth and the numbers of optical modes involved.