为了实现对任意波长激光的自动检测与防护,根据光敏三极管、电磁继电器以及液晶电光效应实验原理，设计了一套激光自动检测和防护装置，并进行了理论分析和实验验证。光敏三极管在受到激光辐射时形成光电流，通过放大电路和电磁继电开关输出5V电压，并使其在较短时间内激活液晶电压开关，使液晶屏在受到激光照射时，对激光基本不透明；而当激光脉冲照射结束时又回到透明状态。结果表明，这种激光防护眼镜的设计方案，可在常态时允许普通和不太强的自然光透过，而在激光照射时阻挡激光透过。

A set of automatic detection and protection device of the laser was designed in order to realize the automatic detection and protection against arbitrary wavelength laser according to the principle of phototriode,electromagnetic relay and liquid crystal electro-optic effect experiments. Based on the theoretical analysis and experimental verification, phototriode photocurrent was formed when exposed to the laser radiation. The amplification circuit and an electromagnetic relay switch were used to control the output voltage of 5V and close liquid crystal voltage switch in a short time. When subjected to laser irradiation, the liquid crystal screen was substantially opaque, and returned to the transparent state at the end of the laser pulse. The results showed a design of laser protective glasses, blocking the laser irradiation and allowing ordinary bright light through at ordinary time.