大功率LED无线光通信的高速脉冲调制技术研究

Studies on accelerated pulse modulation techniques of high power light emitting diodes for optical wireless communication

研究了大功率蓝光LED的光电脉冲响应特性,分析了影响其响应速度的因素,采用小电流负载高速门器件提供脉冲上升沿瞬时过压和下降沿的载流子泄放,实现了LED的光响应加速。利用该方法设计了大电流输出的脉冲调制电路,驱动3W蓝光LED并使其光调制速率提升至4MHz,输出峰值电流达到约800mA。

The pulsed photoelectric response characteristics of the blue power LEDs were investigated. The factors that influence their optical response speed were examined. The gate devices with high speed and small current loading were employed to provide a transient over rated voltage at the rising edge and the carrier draw-out at the falling edges of the drive pulses, thereby the optical response of the LEDs was accelerated. A large current output pulse modulation circuit was designed by this technique, driving a 3W blue LED at the modulation frequency to 4MHz and the output peak current about 800mA.