Refraction and Refractive Index: When light travels in a straight line between two points in a uniform isotropic medium, when it passes through transparent objects with different densities of medium, the phenomenon of refraction occurs due to the different propagation speeds of light in different media. The air shoots light rays that are not perpendicular to the surface of the transparent object (such as glass) into the surface of the transparent object (such as glass), and the light changes direction on its surface and forms a refraction angle with the normal. It is usually expressed in terms of refractive index, which is the ratio of the speed of light in a vacuum to the speed of light in a medium. The higher the refractive index of a substance, the better its ability to refract incoming light.
Performance of optical lens: The lens is the basic optical element that constitutes the optical system of the microscope. The objective lens, eyepiece, condenser and other parts are composed of single lens and multiple lenses. According to the shape of the convex lens, it can be divided into two types: convex lens (positive lens) and concave lens (negative lens).
When a ray parallel to the optical axis passes through a convex lens, it intersects with a point, which is called the focal point, and the plane passing through the intersection and perpendicular to the optical axis is called the focal plane. There are two types of focusing, one is focusing in the object space, called object focusing, the other is focusing in the image space, called image focusing, and the other is focusing in the image space, called image focusing. Square focus plane. When light passes through a concave lens, it forms an upright virtual image, while a convex lens forms an upright real image. Real images can be displayed on the screen, but virtual images cannot.
Several imaging laws of convex lenses:
1. When the object image is located outside the double focal length of the object side of the lens, a reduced inverted real image is formed within the double focal length of the object image and outside the object image;
2. When the object is located at twice the focal length of the object side of the lens, an inverted real image of the same size is formed on the double focal length of the image side;
3. The object image is located within the double focal point on the object side of the lens, and when it is out of focus, an enlarged inverted real image is formed outside the double focal point on the image side;
4. When the object image is located at the focal point of the object side of the lens, the image side cannot be imaged;
5. If the object is within the focal point of the object side of the lens, the image side will not be formed, and an enlarged upright virtual image will be formed on the same side of the lens object side.
The above is today's content about the characteristics of optical lenses in microscopes. Thank you for your patience in reading! If you want to know more about optical lenses, you can contact us.