Two-component compensators of field aberrations of optical systems

Abstract

Subject of study. Two-component optical schemes of compensators of field aberrations of optical systems calculated based on the third-order aberration theory and modular method of optical system design [Izv. Vyssh. Uchebn. Zaved., Priborostr.57, 57 (2014)] are proposed. These compensators enable correction of two aberrations: Petzval field curvature and astigmatism or longitudinal chromatic aberration and lateral color or transverse chromatic aberration. Method. A modular method for the design of optical systems based on the third-order aberration theory was used in the calculation. This method consists of synthesis of the systems using optical elements (modules) with known correcting properties [Izv. Vyssh. Uchebn. Zaved., Priborostr.57, 57 (2014)]. Aplanatic menisci with different linear magnifications and a hyperchromatic lens were used as optical modules. The aplanatic menisci were used to calculate the compensator of Petzval field curvature and astigmatism, whereas the hyperchromatic lens was used to calculate the compensator of longitudinal and transverse chromatic aberrations. Main results. The use of two-component compensators of field aberrations enables significant enhancements in the aberrational properties of the objectives, improves the image quality of optical systems, and increases their optical parameters, particularly the angular field of doublet objectives (fivefold) using the correcting properties of optical modules (menisci and hyperchromatic lens). Practical significance. The introduction of a compensator composed of two aplanatic menisci positioned at a significant distance from each other into the optical system makes it possible to correct such aberrations as field curvature and astigmatism regardless of the number of lenses in the objective and increase the angular field. The introduction of a compensator of chromatic aberrations into an optical scheme of a high-aperture microscope objective with 100×1.25 oil immersion corrects the longitudinal and transverse chromatic aberrations. This makes it possible to cease the use of compensating eyepieces with a complex optical scheme and replace them with standard eyepieces as well as to use a microscope where the optical radiation is detected by a charge-coupled device array or complementary metal oxide semiconductor detector instead of the human eye.