Generation of 208 kV/cm peak field at 2.6 THz in GaP

We present a high-field THz source with a spectral peak centered at 2.6 THz. The setup relies on optical rectification of 0.57 mJ near-infrared pulses to generate THz peak fields up to 208 kV/cm. A phase grating directly etched at the surface of the crystal enables a tilted-pulse-front configuration that optimizes phase-matching conditions. Even when saturation effects are considered, a 5 mJ generation pulse is expected to yield a THz peak field approaching 600 kV/cm. This high-field THz source allows new research opportunities relying on the ability to drive coherent phenomena and nonlinear effects in the region between 2 and 4 THz.