啁啾优化飞秒脉冲抽运GaP产生高功率0.3mW宽带太赫兹波

0.3mW high-power broadband terahertz pulse generation from GaP bumped by the chirp optimized femtosecond pulses

在基于光整流效应的PCF飞秒激光抽运GaP晶体产生宽带THz波的实验中,重点研究了抽运脉冲特性与THz产生效率的关联性.证明了GaP晶体辐射THz波的效率与抽运脉冲的啁啾特性相关;在相同脉冲宽度抽运下,负啁啾脉冲更加有效,这对于基于飞秒激光抽运产生THz波的其他方法有指导意义;并通过优化预赋抽运脉冲的负啁啾量,在抽运功率21 W的条件下,获得了0.3 mW的高重复率宽带THz波输出.

In this paper, a photonic crystal fiber （PCF） femtosecond laser-based GaP terahertz emitter based on optical rectification for generation of high-power, high-repetition rate, broadband THz waves was investigated experimentally, with a focus on the interdependence between the characteristics of the pump pulses and the THz emission efficiency. The results showed that the THz conversion efficiency is dependent on the chirp properties of the pump pulse. A higher efficiency emitter can be obtained when using a negative chirp pump pulse rather than a transform-limited pulse, which can be considered as a universal method to generate THz waves more efficiently with pumping by ultrafast lasers. Using an optimized pump pulse with anomalous dispersion, a THz wave with a maximum power of 0.3 mW was obtained under a pump power of 21 W.