subdiffraction

Subdiffraction refers to the ability to achieve spatial resolutions below the diffraction limit, which is a fundamental constraint in optical microscopy. This limit, known as the Abbe diffraction limit, states that the smallest resolvable feature is approximately half the wavelength of light used. However, various techniques have been developed to overcome this barrier, enabling subdiffraction imaging.

One prominent method is stimulated emission depletion (STED) microscopy, which uses a doughnut-shaped laser beam to deplete the fluorescence of the sample, effectively shrinking the point spread function and allowing for higher resolution. Another technique is structured illumination microscopy (SIM), which employs patterned illumination to encode spatial information into the fluorescence signal, which can then be computationally decoded to achieve super-resolution.

Additionally, techniques such as photoactivated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) utilize the ability to switch individual molecules between a fluorescent and non-fluorescent state. By imaging these molecules one at a time and determining their positions, these methods can achieve resolutions well below the diffraction limit.

Subdiffraction imaging has revolutionized the field of microscopy, enabling the visualization of structures and processes that were previously inaccessible. These advancements have significant implications for biological research, allowing scientists to study cellular structures and dynamics with unprecedented detail.