A microscope ( Greek v. μικρός: small; σκοπεῖν: consider ) is a device that allows you to view magnified objects or depict. These are usually around objects or the structure of objects whose size is below the resolution of the human eye. A technique employing a microscope is called microscopy. Microscopes are an essential tool in biology, medicine and materials science.
The physical principles that are exploited for the magnification effect can be very different nature. The oldest known microscopy technique is the light microscopy, which was developed around since about 1595 glasses or lens grinder makers from the Netherlands and in which an object is observed by one or more glass lenses. The maximum physically possible resolution of a conventional optical microscope is limited and dependent on the wavelength of the light used for most about 0.2 microns. This limit is called the Abbe limit, since the underlying regularities described the late 19th century by Ernst Abbe.
A higher resolution allow electron microscopes, which have been developed since the 1930s, since electron beams have a smaller wavelength than light. Atomic force microscopes work on a different principle and have very fine needles with which the surface of objects being scanned. Other types are listed below.
Imaging and scanning- microscopy
Conventional light microscopy types based on a principle of imaging: Similar to the photograph an image in the unit by a series of lenses passing produced, which is seen or taken in a single piece.
Some light microscopic method and especially microscopes, based on other physical principles, on the other hand set (English: scanning) on a scanning of the object, in which the individual points of the enlarged image are sequentially line by line generated. These include, for example, laser scanning microscopes, electron microscopes and atomic force microscopes.
Microscopy methods on the physical principle
Light microscopes, electron microscopes and scanning probe microscopes are built in numerous variants and uses, which are presented in the review articles. In addition to these, there are also microscopes based on different physical principles:
- X-ray microscopy
- Ultrasonic microscopy or acoustic microscopy
- Helium - ion microscopy
- Focused-ion -beam microscope ( FIB)
- Photonic force microscope
- Magnetic resonance microscope
- Scanning SQUID microscope
- Neutron microscope