用蓝色光二极管双光子跃迁光电流信号测量掺钛蓝宝石飞秒激光脉冲宽度，实验高精度地记录了二阶干涉自相关曲线及其精细结构。由于用蓝色光二极管双光子跃迁代替了常用的二次谐波，而且光信号直接转化为电信号，从而使飞秒激光脉冲宽度的测量大为简化。 The pulse width of titanium-doped sapphire femtosecond laser was measured by two-photon transition photocurrent signal of blue photodiode. The second-order interference autocorrelation curve and its fine structure were recorded with high accuracy. Due to the blue photodiode two-photon transition instead of the common second harmonic, and optical signals directly into electrical signals, so that femtosecond laser pulse width measurement is greatly simplified.