Study on conversion efficiency of optical-to-terahertz in optical rectification

摘要

Optical rectification of ultra-short laser pulses is an attractive technique for efficient generation of terahertz pulses. An analytical expression of the optical-to-terahertz conversion efficiency in optical rectification by the use of the method of tilted-pulse-front pumping has been derived and used to simulate the maximum optical-to-terahertz conversion efficiency. The variations of the conversion efficiency of optical-to-terahertz with the length of crystal, the intensity and the pulse duration of the pumping ultra-short laser have been investigated, both in numerical and analytical solutions. In addition, the absorption of terahertz wave in LiNbO_3 has also been taken into account. The results show that, the optical-to-terahertz conversion efficiency increases with the intensity of pump pulse and the length of crystal, whereas decreases with the increasing of the pulse duration for the case of the relatively large pulses duration.