The history of optical microscope

Abstract

This article describes the history of the optical microscope. The convex lens, an important component of the microscope, was already in use during the ancient era as a tool to create fire from sunlight. The quality of the lens improved in the 11th and 12th centuries and had begun to be used as a microscope component by the end of the 16th century. In the 17th century, innovation of the optical microscope accelerated the study of biological specimens. Robert Hooke designed a two-lens microscope and observed various microorganisms. He published “Micrographia” in 1665, in which the term “cell” first appeared. Another contributor to the microscope in the same period was Leeuwenhoek, who constructed a single lens microscope and discovered bacteria. In 1857, Zeiss, with the cooperation of Abbe and Schott, manufactured a stand type modern microscope that achieved a spatial resolution of 0.2 μm. Their microscope significantly contributed to subsequent discoveries in medical biology. Due to the wave nature of light, the spatial resolution of an ordinary microscope is limited to 0.2 μm. To overcome this limitation, various microscope configurations such as a two-photon laser-scanning microscope, a near-field scanning optical microscope, and a photoactivated localization microscope were developed. For the nonstaining visualization of biological specimens, optical microscopy utilizing a nonlinear optical phenomenon was proposed. Currently, the second harmonic generation microscope and the coherent Raman scattering microscope are widely used and several examples of these microscopic results are presented in this article.