声光调制驱动源数字线性电压控制技术研究

Research on Digital Linear Voltage Control Technology of an Acousto-Optic Modulation Driving Source

针对声光器件固有的非线性特性,基于单片机技术和线性电压补偿技术,设计了具有48级灰度的数字线性电压控制系统.该系统是利用48组电阻分压器把0~5 V（D.C.）分为48级档次电压,通过单片机AT89C51控制模拟电子开关电路CD4051选择控制电压,对声光调制驱动源的载波信号进行调制,得到对应的衍射光强,对CD4051应用技巧、线性电压补偿原理和实现方法进行了研究.实验结果表明：补偿前衍射光强与控制电压的线性相关系数为92.68%,补偿后线性相关系数可达98%,衍射效率提高了7%.把声光调制技术、单片机技术和线性电压补偿技术相融合,实现了声光调制的数字化和线性化,在激光大屏幕图文显示和激光外差干涉技术等领域具有广泛的应用.

Due to the inherent nonlinear characteristic of acousto-optic devices, a new digital linear voltagecontrol system with 48 grades in linear gray scale was designed, which is based on the single chip microcom- puter （SCM） and linear voltage compensation technology. The system divides 0-5 V （D. C. ） into 48 grades in voltage by 48 groups of resistor divider, then the CD4051 which are controlled by SCM choose the voltage values, which was used to modulate the carrier signal of the acousto-optic modulation（AOM） driving source, and the corresponding diffraction intensity was obtained. The application skills of CD4051, the principle and realization method of linear voltage compensation were discussed. The experimental results show that the lin- ear correlation coefficient of the diffraction intensity vs. control voltage is 92.68 % and 98 % respectively, and the diffraction efficiency is increased by 7% before and after linear voltage compensation. The integration of AOM, SCM and linear voltage compensation technology made the digitalization and linearization of AOM come true, and the system has a widely use in the fields of laser large screen character ＆ document display and laser optical heterodyne interference technology.