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We present high-power single-cycle carrier-envelope phase locked THz pulses at a central frequency of 2.1 THz with MV/cm electric field strengths and magnetic field strengths beyond 0.3 T. The THz radiation is generated by optical rectification in an organic salt crystal 4-N,N-dimethylamino-4′-N′-methyl stilbazolium tosylate called DAST pumped with the signal wavelength of a powerful optical parametric amplifier. Conversion efficiencies of more than 2% are reported.

We present the generation of high-power single-cycle terahertz (THz) pulses in the organic salt crystal 2-[3-(4-hydroxystyryl)-5.5-dimethylcyclohex-2-enylidene]malononitrile or OH1. Broadband THz radiation with a central frequency of 1.5 THz (λ(c)=200 μm) and high electric field strength of 440 kV/cm is produced by optical rectification driven by the signal of a powerful femtosecond optical parametric amplifier. A 1.5% pump to THz energy conversion efficiency is reported, and pulse energy stability better than 1% RMS is achieved. An approach toward the realization of higher field strength is discussed.

High-field terahertz (THz) single-cycle pulses with 1.5 MV/cm are generated by optical rectification in the stilbazolium salt crystal 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium 2,4,6-trimethylbenzenesulfonate. We show experimentally that the generated THz transient carrying 5 octaves (0.15 to 5.5 THz) undergoes a complex time-frequency evolution when tightly focused, and we present a model based on three independent oscillating dipoles capable to describe this anomalous field evolution. Finally, we present a method to control the absolute phase of such supercontinuum THz pulses as an essential tool for future field-sensitive investigations.

We derive an expression describing pre-compensation of pulse-distortion due to saturation effects in short pulse laser-amplifiers. The analytical solution determines the optimum input pulse-shape required to obtain any arbitrary target pulse-shape at the output of the saturated laser-amplifier. The relation is experimentally verified using an all-fiber amplifier chain that is seeded by a directly modulated laser-diode. The method will prove useful in applications of high power, high energy laser-amplifier systems that need particular pulse-shapes to be efficient, e.g. micromachining and scientific laser-matter-interactions.