摘要

Optical rectification is one of the most important techniques for efficient terahertz (THz) radiation generation. However, the strong THz absorption caused by the free electrons in nonlinear crystal limits the further increasing of the THz radiation generation efficiency. The interaction mechanism between the femtosecond laser and the nonlinear crystal has been analyzed and the related theoretical model has been built up. And the theoretical model of the THz radiation generation efficiency in optical rectification by tilted-pulse-front pumping has also been built. On the basis, the influence of the central wavelength, the pulse duration, and the temperature on the THz radiation generation efficiency has been analyzed quantitatively. The results show that the THz radiation generation efficiency increases first and then decreases with the increasing of the intensity of pump pulse. In addition, the maximum THz radiation generation efficiency can be achieved by cryogenic temperatures and the optimized parameters of the pump pulses and the nonlinear crystal.

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