Generation of high-energy terahertz pulses

Apparatus and method for the efficient generation of intense terahertz (THz) radiation by a tilted pulse front method. The drawback of the existing solution is that mapping errors result in distortion of the pumping pulse, which is detrimental to the efficiency of THz excitation. The contact grating solution is designed to overcome this, but in cases where a low-period grating is required, technical difficulties arise in its implementation. The inventive step is based on a combination of the two solutions, so that the pulse front tilting would be implemented in two steps. Hence, the mapping error can be reduced as the beam would arrive at the mapping element with a smaller angular dispersion. At the same time, the period length of the grating to be created on the crystal surface would be larger than in the case without pulse front pre-dipping. By optimising the degree of pre-casting, THz generation with a more favourable efficiency can be achieved.