被动锁模Nd玻璃激光器输出以非共线倍频的方式在LiIO3内产生二次谐波,用一维二极管列阵将谐波强度的空间分布显示于通用的示波器,根据脉宽与谐波光强分布的宽度之间关系,可得出脉冲串的平均脉冲宽度。

In this paper we describe an experimental set-up in which a simple scanning photodiode array is used for display and the autocorrelation trace is shown on a conventional oscilloscope. The pulses come from a passively mode-locked Nd glass laser at 1.06um. After expanding and splitting, laser beams produce the noncollinear second harmonic (NSHG) in a LiIO3 crystal. According to the dependence of the duration of the fundamental frequency beam on the half width of the NSHG spatial intensity distribution in our ease, it has been measured that the average duration of the pulse train is (19+2) ps, a sharp peak of 0.4ps being superimposed on a broad background. This setup is of low cost and pratical. Some calculations dealing with the design and operation are given.