飞秒光学脉冲电场包络一阶时域微分实验研究

First-Order Time Differentiation Experiment of Femtosecond Optical Pulse Electric Field Envelope

光学脉冲的时域微分技术在时空测量领域有着重要应用,利用微分脉冲可使时空测量的精度达到或超越标准量子极限。分别利用双折射晶体和傅里叶脉冲整形系统两种方法对中心波长为813nm、脉宽为130fs的脉冲电场包络进行了一阶微分实验研究。利用双折射晶体得到的脉冲电场包络一阶微分能量转换效率为0.36%,电场强度的频谱分布只在中心频率附近的光谱半峰全宽范围内可与理论值较好地吻合,重合度达到91.36%,距离中心频率越远,与理论值差距越大。利用傅里叶脉冲整形系统得到的脉冲电场包络一阶微分能量转换效率达到11.10%,在空间光调制器的有效调制范围内,电场强度与理论值的重合度超过98.37%。与基于双折射晶体的脉冲微分方法相比,基于傅里叶脉冲整形系统的脉冲微分方法具有更高的能量转换效率,与理论值吻合的光谱范围更大,且能方便地产生任意阶数的微分脉冲,能更好地满足高精度时间同步领域的应用需求。

The light pulse differentiation technology in time domain has shown important applications in the field of time-space metrology,and it makes the measurement precision reach or beyond the standard quantum limit.In this paper,a first-order differentiation experiment of the pulse electric field envelope with a central wavelength of813 nm and pulse duration of 130 fs has been implemented based on the birefringent crystal and the Fourier pulse shaping system separately.Based on birefringent crystals,the pulse electric field envelop is achieved with energy conversation efficiency of 0.36%.By comparing the spectral distribution of the shaped pulse with the theoretical value,we find that a relatively good overlap can be seen within the full wavelength half maximum range near the central wavelength with an overlap rate of 91.36%,and the difference between them increases as the distance from the central frequency increases.For the first-order differentiated pulse electric field envelope generated by the Fourier pulse shaping system,the energy conversation efficiency rises to 11.10%.Meanwhile,its overlap rate with the theoretical value is over 98.37% within the effective modulation range of the utilized spatial light modulator.Compared with the former method,the latter can achieve much higher energy conversation efficiency and larger overlap spectral range with the theoretical value.Furthermore,as it can be used to achieve random-order differentiated pulses,the Fourier pulse shaping system can meet the demand of high-precision time synchronization applications.