A microscope is an optical instrument that magnifies tiny objects and is widely used in scientific research and education. Its basic principle is to use the refraction and reflection of light to magnify the sample through multiple lens systems, so that the human eye can observe the microscopic structures that cannot be directly seen under normal circumstances.

In the design of a microscope, several different types of lenses are usually included. The most important thing is the objective and the eyepiece. The objective lens captures and magnifies the light in the sample, while the eyepiece further magnifies the image created by the objective lens. With the synergistic action of these two lenses, the microscope can achieve high magnification and clear imaging effects.

Modern microscopes can be roughly divided into two categories: optical microscopy and electron microscopy. Optical microscopes use visible light for imaging and are suitable for observing biological samples such as cells and tissue slices. It has the advantage of simple operation and relatively low cost, but its resolution is limited by the wavelength of light. In general, the maximum resolution of an optical microscope is about 200 nanometers.

In contrast, electron microscopes, which use electron beams for imaging, are able to achieve much higher resolution and are often able to observe structures at the nanoscale. This makes it widely used in the fields of materials science, nanotechnology and biomedicine. However, the operation of electron microscopy is relatively complex, the sample preparation process is also more complicated, and the use cost is high.

The invisibility microscope is a new technology, which can observe the internal structure of the sample without damage, and has important application potential. This technique relies on special imaging principles, such as fluorescence, phase contrast, and confocal methods, allowing researchers to observe dynamic processes in living samples.