How Do I Choose the Best Newtonian Telescope?

Newton Telescope is a reflecting telescope invented by British astronomer Isaac Newton (1643-1727). The main mirror uses a parabolic mirror, and the second mirror is a flat diagonal mirror. It works by using a curved mirror to reflect light to a focal point. This design method is several times higher than using a lens to magnify an object.

Newton (Isaac Newton, 1642-1727) is a great British scientist whose research fields include physics, mathematics, astronomy, natural philosophy, alchemy and theology. Newton invented calculus, discovered the law of universal gravitation, created classical mechanics, designed and manufactured the first reflective telescope, etc., and was hailed as the most influential scientist in human history. As Engels put it: "Newton created scientific astronomy by inventing the law of gravity ^[1]

The common-path heterodyne interference method was used to analyze the polarization characteristics of the Newtonian telescope. According to Fresnel's law, the reflectivity formulas of incident light S-polarized light and P-polarized light incident on various points of the telescope were obtained. A schematic diagram of an experimental device for measuring the polarization characteristics of a Newtonian telescope by a common-path heterodyne interference method is given. Using 632.8nm heterodyne light source, the Newtonian telescope's influence on S-polarized and P-polarized reflection coefficients, phase differences, and polarization of incident light were analyzed. Corresponding change curves were drawn according to different incident angles. The results show that the Newton telescope coated with aluminum film has little effect on the polarization characteristics of incident light, the difference between the reflection coefficients of S-polarized light and P-polarized light is less than 0.01, and the degree of polarization does not exceed 0.07, which is suitable for laser remote sensing polarization imaging Receiving system. ^[4]