Simple (one lens) microscope and the compound (many lenses) microscope are the two basic configurations of optical microscope. And all of them share the same basic components. The eye piece or the ocular is a canister that contains two or more lenses that brings the image to focus for the eye.
The objective lens is another cylinder that contains one or more lenses to gather light from the sample. The visual mechanism of a contemporary microscope is multifaceted and for a microscope to work well, every optical path has to be perfectly set up and controlled. The stage is a platform below the objective lens that supports the specimen being experimented, and at the heart of the stage is a spherical hole in which light shines to elucidate the specimen. The illumination source is placed below the stage to control and provide light in number of ways. However, most microscopes have their own controllable illumination source that is focused through an optical device called a condenser with diaphragms and filters to control the quality and concentration of the light. One particular condenser is called Abbe condenser. Other types of optical microscope includes the inverted microscope for studying cell cultures in liquid, the research microscope, the petrographic microscope for the study of minerals or other crystalline materials, the polarizing microscope, fluorescence microscope and the phase contrast microscope.
Scanning probe microscopes is a branch of microscopy used to measure properties of surfaces. It is founded with the invention of the scanning tunneling microscope in 1981. Scanning probe microscope covers a number of related technologies such as imaging and measuring surfaces on a fine scale, down to the level of molecules and atoms. During the first applications this instrument was used exclusively for measuring surface topography but this device evolved as one of the most powerful tools for surface metrology of our time. Scanning probe microscopes are the pioneers in producing real space image of atomic arrangements on a flat surface, and commonly used to perform very precise, three dimensional measurements on the nanometer-to-micron scale.
The three types of scanning probe microscope are the atomic force microscopy (AFM) which measures the interaction force between the tip and the surface. The second type is the scanning tunneling microscopy (STM) that measure the weak electrical current flowing between the tip and sample as they are held a very distance apart. The last type is the near field scanning optical microscopy (NSOM) that scans the tiniest light force very close to the sample. An image will be formed after the detection of this light energy and provides a resolution below that of the conventional light microscope.