Abstract-Broadband terahertz pulse generation driven by an ultrafast thin-disk laser oscillator

Clément Paradis, Jakub Drs, Norbert Modsching, Olga Razskazovskaya, Frank Meyer, Christian Kränkel, Clara J. Saraceno, Valentin J. Wittwer, and Thomas Südmeyer

Fig. 1 Experimental setup for THz generation driven by the output of an ultrafast thin-disk laser oscillator. The inset (a) shows (from left to right) the optical spectrum, the autocorrelation trace and the output beam profile of the laser; the inset (b) shows the beam profile of the near-infrared laser at the focus. BPD: balanced photo-detector; DM: dispersive mirror; OAPM: off-axis parabolic mirror; OC: output coupler; QWP: quarter-wave plate; T: transmission; WP, Wollaston prism; wIR: infrared beam radius.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-20-26377

We demonstrate broadband THz generation driven by an ultrafast thin-disk laser (TDL) oscillator. By optical rectification of 50-fs pulses at 61 MHz repetition rate in a collinear geometry in crystalline GaP, THz radiation with a central frequency at around 3.4 THz and a spectrum extending from below 1 THz to nearly 7 THz are generated. We realized a spectroscopic characterization of a GaP crystal and a benchmark measurement of the water-vapor absorption spectrum in the THz range. Sub-50-GHz resolution is achieved within a 5 THz bandwidth. Our experiments show the potential of ultrafast TDL oscillators for driving MHz-repetition-rate broadband THz systems.

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