Johnson D C
Appl Opt. 1973 Sep 1;12(9):2192-7. doi: 10.1364/AO.12.002192.
The measurement of the absorption coefficient of highly transparent materials using Pinnow and Rich's calorimetric technique requires that the material be fabricated into the shape of a cylindrical rod. Since crystalline materials are more readily fabricated into rods with a square cross section, Pinnow and Rich's calorimetric technique is extended to such samples. This is accomplished by calculating the temperature distribution that is produced in a sample of material having a square cross section by the passage of a Gaussian light beam through the sample. A simple relationship between the sample surface temperature and its absorption coefficient is derived that is valid to within 2% of the exact relationship for typical conditions that occur when employing the calorimetric method. The results of a calorimetric measurement of the absorption coefficients of a single crystal of potassium dihydrogen phosphate at a wavelength lambda = 1.06 microm are reported. These are shown to be in good agreement with values reported earlier that were obtained by U. S. Averbakh, I. A. Batyrea, and V. O. Bespalov using a spectrophotometric technique.
使用皮诺和里奇的量热技术测量高透明材料的吸收系数，要求将该材料制成圆柱形棒的形状。由于晶体材料更容易被制成具有方形横截面的棒，因此皮诺和里奇的量热技术被扩展到此类样品。这是通过计算高斯光束穿过具有方形横截面的材料样品时在样品中产生的温度分布来实现的。推导出了样品表面温度与其吸收系数之间的简单关系，在采用量热法时出现的典型条件下，该关系与精确关系的误差在2%以内。报告了在波长λ = 1.06微米下对磷酸二氢钾单晶吸收系数进行量热测量的结果。结果表明，这些结果与美国的阿韦尔巴赫、I. A. 巴捷里亚和V. O. 别斯帕洛夫早期使用分光光度技术获得的值非常吻合。
