NSom

NSOM, which stands for Near-field Scanning Optical Microscopy, is a type of optical microscopy that uses a sharp probe to scan a surface and produce high-resolution images. This technique uses the principle of near-field optics to overcome the limitations of conventional light microscopy.

Unlike traditional optical microscopy methods which rely on diffraction-limited resolution, NSOM uses a small probe with a diameter of around 10-100 nanometers to focus on a specific region of the sample. This allows for image resolutions as high as 10-20 nm, making it possible to observe structures and features at the molecular or atomic level.

The application of NSOM includes fields such as biomedicine, materials science, and nanotechnology. Researchers use NSOM to study the molecular arrangement of biological samples, the structure of nanostructured materials, and the properties of individual molecules. It also enables the study of chemical and biological interactions at the nanoscale.

There are two types of NSOM: optical fiber based NSOM and sharp probe based NSOM (also known as aperture-based NSOM). The optical fiber based NSOM involves using a single-mode optical fiber as a probe, while the sharp probe based NSOM uses a sharp metal tip as the scanning probe.

NSOM has some limitations, such as its sensitivity to the sample's preparation and the environment, which may affect the quality of the images. Nevertheless, NSOM has contributed significantly to the advancement of various scientific fields, particularly in the study of nanoscale structures and their properties.

It is worth noting that NSOM is capable of high-speed imaging, and some commercially available systems can achieve image acquisition rates of up to 100 frames per second. This has opened up new possibilities for tracking dynamic processes at the nanoscale.