The performance of a microscope is influenced by several factors
The main factor determining the performance of Nikon microscopes is their resolution, also known as resolution or resolution. However, physical quantities such as magnification and clarity are closely related to the resolution of Nikon microscopes
We know that microscopes are complex coaxial optical systems. This system consists of main imaging elements such as a light source, aperture light bar, spotlight, and objective lens. The eyepiece is just an optical component that directly magnifies and projects the object onto the screen (including the human retina). The light source may be incoherent sources such as sunlight or light, or coherent sources such as point light.
In the 1870s, German scholar E. Abbe laid the foundation for the theory of microscopic imaging. Modern physics optics uses updated experiments to further elucidate the essence of the spectrum transformation principle in Abbe imaging theory (Fourier spectrum transformation optics).
The key imaging component in the microscope imaging optical path is the objective lens. There are countless planes between the light source and the front lens of the objective lens, with corresponding conjugate planes behind the objective lens. However, according to Abbe's theory, the object plane O in the microscope corresponds to the conjugate plane O, which is the image plane O, and the conjugate plane I, which corresponds to the light source I. These are two important pairs of planes in the imaging system. To understand the imaging process of Nikon microscopy, we must study the optical processes that occur on these two corresponding conjugate planes.
Within the angle range of the incident beam limited by the aperture light bar in the microscope, it is directly transformed into an illuminating light source for illuminating the specimen through a condenser. The light on the aperture beam plane forms images on or near the focal plane behind the objective lens. Abbe referred to this image as the first imaging in the microscopic imaging path. We cannot ignore the importance of the quality of the first imaging. Firstly, the aperture light bar limits the necessary incident angle for imaging the beam of light. This means that the more suitable brightness for observing objects under a microscope is determined by this. Secondly, the imaging light on different planes from the three-dimensional structure of the specimen is also determined by this. In short, the moderate contrast of the object image and the clarity of the object image contour in the Nikon microscope are determined by this.
If we insert the specimen into the imaging path of the Nikon microscope, the first imaging system will be damaged. The aperture light bar image can no longer be seen in the mirror tube. At this point, the details of the specimen become illuminated and imaged on the retina or screen behind the eyepiece. Abbe called this the second imaging of the microscope. The imaging process of specimen details cannot be explained by geometric optics. Because the imaging light is refracted, birefringent, diffracted and scattered on this plane, and the intensity distribution of the light is changed by the details of the specimen. The light information on the Fourier spectrum plane is transformed and projected onto the screen. In various optical microscopes, based on this principle, various interference components are used to map the details of the specimen into objects with contrasting light and dark or contrasting dark and light. This is the imaging principle of various microscopes that we will discuss in detail in the future.
