摘要：
现有声光可调谐滤光器 (AOTF) 调谐关系大多忽略旋光性影响, 忽略旋光性将影响声光滤波器的准确设计, 并会进一步影响其滤波性能, 故推导了旋光率与衍射波长之间的关系, 进而得到考虑旋光性的AOTF衍射频率-波长调谐关系;针对AOTF衍射波长在不同温度下存在温漂, 因此影响AOTF的光谱分辨率, 从温度影响超声声速出发, 分析得到AOTF衍射波长在不同温度下与驱动频率的关系, 提出在不同温度下采用频率修正的方式跟踪衍射波长.根据考虑旋光性推导所得AOTF调谐关系、考虑到实时跟踪温度、频繁变换驱动频率容易对系统造成破环, 影响使用效率, 因此采用10°C为一个温度段, 在一个温度段内根据中间温度使用一个驱动频率对AOTF进行调控, 每一温度段有相应的驱动频率-衍射波长对应关系, 叙述了具体的实现办法, 并做了相应的实验验证.实验表明, 通过频率修正之后在相应温度下得到的衍射波长, 与普通室温未修正频率下得到的衍射波长相比, 前者与目标波长更相近, 误差减小一个数量级.为AOTF在不同温度下的高精度光谱测量提供了重要的依据, 具有重要的实用价值.%Existing AOTF tuning relationship mostly ignores the optical rotation effect, but it will effect the accurate design of acousto-optic tunable filter, and will further influence its filtering performance, so the relationship between the specific rotation rate and diffraction wave length was deduced, then the AOTF tuning relationship considering the optical activity was acquired; aiming at temperature drift of AOTF diffraction wave under different temperature, therefore affecting the spectral resolution of AOTF, this article starting from the ultrasonic velocity influenced by temperature, the relationship between the wavelength and driving frequency under different temperatures was gained by analyzing, and the new method of frequency correction tracking diffracted wavelengths was put forward under different temperatures. According to AOTF tuning relationship considering the optical rotation, and considering the real-time tracking temperature, repeatedly conversion driving frequency will easily cause damage to the system, and will further affect the efficiency, so we adopted 10 °C as a period of temperature, within a period of using a driver frequency to adjust AOTF according to the medium temperature, and every period has the corresponding relation of driving frequency-diffraction wavelength. The paper described the specific measures for the implementation and made the corresponding experiment. The results showed that compared to no frequency correction with normal room temperature, the diffraction wavelength was close to the target wavelength operated by the frequency correction under the corresponding temperature, and the error of the correction method is 1 order of magnitude lower than that without correction. The method provides an important basis for high accuracy spectrum measurement with AOTF under different temperatures, which has important practical value.
