采用同一电光器件对发射和接收光束同时开关的原理，提出了一种新颖的激光测距方法。光源发出的连续激光被待测目标反射后，往返两次通过光源端的电光晶体，在晶体上施加边沿急速变化的电压，利用其高速响应的开关特性，同时对往返光线产生影响，截取出一段包含激光往返待测距离所需时间信息的光强变化曲线。实验中利用雪崩管电路实现了纳秒级的高压上升沿，并利用单轴晶体的双折射和全内双反射性质，用特殊结构的单块LiNbO3晶体实现了该方法的测距装置。示波器分析的实验结果验证了该方法的可行性，从而为激光测距开拓了一种新的思路。

By simultaneous switching of transmitting and receiving beams in an electro-optical device, a novel laser ranging method is proposed. Continuous wave (CW) laser emitted by laser transmitter goes forward to the measured object, being reflected by the object, then goes back to the transmitter. Close to the transmitter, an electro-optical crystal is added into the round-trip light rays. High voltage curve with the steep enough edges is added on the crystal. Because of the high speed switch effect, the crystal operates on the transmitting and receiving beams at the same time. So light pulses, whose width T contains the required range information, are cut off and detected. In experiments the changing time of high voltage is about several nanoseconds realized by avalanche triode circuit. And based on double refraction and total internal double reflection effect in crystal, a single block LiNbO3 crystal with special shape is designed as the main device of this method. The feasibility of the new idea is proved by the results from oscillograph. So a brand-new way for the laser ranging is provided.