Abstract Mach-Zehnder and conoscopic interferometry are used to explore photoelastic properties of anisotropic crystal materials. In a number of cases an application of both techniques significantly improves an accuracy of piezooptic and photoelastic measurements. The performance of such combined approach is demonstrated on tetragonal lithium tetraborate (LTB) single crystals, as an example. Special attention is paid to methodological and metrological aspects, such as measurement accuracy and the quantitative error analysis of the resulting measurements. Performing the interferometric measurements for different geometries of piezooptic coupling the full sets of piezooptic and photoelastic tensor constants of LTB crystals have been determined. The acoustooptic efficiency, on the other hand, has been evaluated using the magnitudes of photoelastic constants derived from the piezooptical measurements. For the geometries with strong photoelastic coupling LTB demonstrates quite large acoustooptic performance with figure of merit value, М2, achieving 2.12 × 10–15 s3/kg. It is several times larger than that of strontium borate crystals, nowadays the best acoustooptic material in deep-ultraviolet spectral region.

中文翻译：

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通过结合 Mach-Zehnder 和锥光干涉测量法表征光弹性材料：在四方四硼酸锂晶体中的应用

摘要 Mach-Zehnder 和锥光干涉仪被用来探索各向异性晶体材料的光弹性特性。在许多情况下，这两种技术的应用显着提高了压电和光弹性测量的准确性。例如，在四方四硼酸锂 (LTB) 单晶上证明了这种组合方法的性能。特别注意方法学和计量学方面，例如测量精度和结果测量的定量误差分析。对不同几何形状的压电耦合执行干涉测量，已经确定了 LTB 晶体的全套压电和光弹性张量常数。另一方面，声光效率，已经使用从压电测量得出的光弹性常数的大小进行了评估。对于具有强光弹性耦合的几何结构，LTB 表现出相当大的声光性能，具有品质因数，М2，达到 2.12 × 10–15 s3/kg。它比硼酸锶晶体大几倍，是当今深紫外光谱区最好的声光材料。