Kastelik Jean-Claude, Benaissa Hichem, Dupont Samuel, Pommeray Michel
IEMN CNRS 8520, Opto-Acousto-Electronic Department, University of Valenciennes,Le Mont Houy, 59313 Valenciennes Cedex 9, France.
Appl Opt. 2009 Mar 1;48(7):C4-10. doi: 10.1364/ao.48.0000c4.
We present a bifrequency acousto-optic tunable filter (AOTF) for applications using polychromatic laser beams. The acousto-optic device is based on two successive anisotropic interactions in paratellurite: the first takes place with an acoustic shear wave tilted at 10 degrees from the [110] axis, while the latter is provided by the acoustic shear wave propagating collinear to the [110] axis. It is then demonstrated that the sidelobes of the impulse response to optical wavelengths of such a bifrequency AOTF are greatly reduced. General expressions of operating frequencies, spectral bandwidths, and acoustic powers are derived. Numerical computations have been drawn for paratellurite. The bifrequency AOTF has been tested using a multiline beam radiated by an argon laser. According to the spectral power distribution of this polychromatic laser beam, the most critical configurations of wavelength filtration have been considered. Experimental results confirm the theoretical predictions.
我们展示了一种用于多色激光束应用的双频声光可调滤波器（AOTF）。该声光器件基于黄碲矿中的两个连续各向异性相互作用：第一个相互作用是由与[110]轴倾斜10度的声学剪切波产生的，而第二个相互作用是由与[110]轴共线传播的声学剪切波提供的。结果表明，这种双频AOTF对光波长的脉冲响应的旁瓣大大降低。推导了工作频率、光谱带宽和声功率的一般表达式。已针对黄碲矿进行了数值计算。使用氩激光辐射的多线光束对双频AOTF进行了测试。根据该多色激光束的光谱功率分布，考虑了波长过滤的最关键配置。实验结果证实了理论预测。
