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arXiv · 1512.03941

THz generation using a reflective stair-step echelon

Benjamin K. Ofori-Okai·Prasahnt Sivarajah·W. Ronny Huang·Keith A. Nelson
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Abstract

We present a novel method for THz generation in lithium niobate using a reflective stair-step echelon structure. The echelon produces a discretely tilted pulse front with less angular dispersion compared to a high groove-density grating. The THz output was characterized using both a 1-lens and 3-lens imaging system to set the tilt angle at room and cryogenic temperatures. Using broadband 800 nm pulses with a pulse energy of 0.95 mJ and a pulse duration of 70 fs (24 nm FWHM bandwidth, 39 fs transform limited width), we produced THz pulses with field strengths as high as 500 kV/cm and pulse energies as high as 3.1 $μ$J. The highest conversion efficiency we obtained was 0.33%. In addition, we find that the echelon is easily implemented into an experimental setup for quick alignment and optimization.

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Benjamin K. Ofori-Okai, Prasahnt Sivarajah, W. Ronny Huang, Keith A. Nelson. 2015-12-12. THz generation using a reflective stair-step echelon. https://doi.org/10.1364/oe.24.005057

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