The influence of absorption on the refractive index determination by the minimum deviation method

Abstract

The light through the prismatic absorbing medium are studied, the angle of refraction and the angle of deviation have been obtained. Numerical analysis shows that, when the imaginary part of the absorbing medium exists, the incident angle is not equal to the refraction angle at the minimum deviation angle, which is inconsistent with the condition of the minimum deviation angle of the transparent medium. The refraction angle of the absorbing prism is compared with that of the transparent prism, with the increase of the incidence angle, the former is less than, then greater than, and finally less than the latter, the deviation angle also has a similar law. Therefore, the effect of the absorption of the medium on the refractive index measurement by the minimum deviation angle method must be considered. When the incidence angle is large, the difference of deviation angle between the absorption prism and the transparent prism is close to zero. When the prism vertex angle is small, the difference of deviation angle between the absorption prism and the transparent prism is close to zero too.