Scanning apertureless fluorescence microscope

Patent Granted There exist NSOM which can be operated in so-called aperture mode and NSOM for operation in a non-aperture mode. As illustrated, the tips used in the apertureless mode are very sharp and do not have a metal coating. Though there are many issues associated with the apertured tips (heating, artifacts, contrast, sensitivity, topology and interference amongst others), aperture mode remains more popular. This is primarily because apertureless mode is even more complex to set up and operate, and is not understood as well. There are five primary modes of apertured NSOM operation and four primary modes of apertureless NSOM operation. The major ones are illustrated in the next figure. Other types of NSOM operation utilize “active tip" schemes, where the tip is functionalized with active light sources such as a fluorescent dye [18] or even a light emitting diode that enables fluorescence excitation.