用蓝色光二极管测量掺钛蓝宝石飞秒激光脉冲宽度

Femtosecond Optical Pulse Characterization with Blue Light Emitting Diodes

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 characterization of femtosecond optical pulses for Ti∶sapphire laser output is conducted with two photon induced transitions in blue light emitting diodes. Excellent phase relationship between the two separated pulses are recorded from the fringes of the two photon induced, second order correlation function. It is demonstrated that the two photon induced current can greatly simplify the femtosecond pulse characterization by direct converting the photon signal to current signal.