Abstract
In this paper, we present theoretical foundations of first-order design of an imaging refractometer. This refractometer may be used to measure the refractive index of liquids over a wide range. Refractive index reconstruction techniques are presented, and analytical reconstruction expressions are derived. The validity of the derived formulas is tested and is in good agreement with Gaussian reduction results. Design examples are provided and discussed. Limitations of the proposed measuring techniques are discussed, and theoretical models as well as numerical examples for the accuracy are presented. (C) 2020 Optical Society of America