声光可调谐滤波器驱动系统设计

声光可调谐滤波器(AOTF)作为一种新型分光元件,其功能的实现可通过对驱动电压的调节来控制衍射光光强,特别是对于非共线型AOTF,通过控制超声波频率能获得更高的衍射效率。该文介绍了基于单片机(SCM)和直接数字频率合成器(DDS)的AOTF的驱动系统设计,该系统主要由信号源模块、功率放大模块及上位机模块3部分组成。单片机用来实现上、下位机的通信及对DDS的控制功能,通过调整频率控制字使DDS输出不同频率的正弦信号;功放模块通过三级级联方式,无需进行阻抗匹配设计,且频带范围宽,接近3个倍频程。该系统可实现单频和扫频两种工作方式,驱动频率为30~200 MHz,驱动功率可达33dBm,结构简单,稳定性好。

Design of Driving System of Acousto optic Tunable Filter

As a new type of spectral components, the acousto optic tunable filter (AOTF) can control the diffraction ligh intensity through regulating the driving voltage, especially for the non colinear AOTF, higher diffraction efficiency can be obtained by controlling the ultrasonic frequency. The design of AOTF driving system based on single chip microcomputer (SCM) and direct digital frequency synthesizer (DDS) is presented in this paper. The system is mainly composed of signal source module, power amplification module and PC module. The single chip microcomputer is used to implement the communication between SCM and PC and the control function of DDS, by adjusting the frequency control word, the DDS outputs the sine signals of different frequency; the power amplifier module does not need impedance matching design through the three level cascading, and the frequency range is nearly 3 octave. The system has two operating modes of single frequency and frequency sweeping, its driving frequency range is 30~200 MHz, driving power can be up to 33 dBm, and has the features of simple structure and good stability.