Breaking the Diffraction Barrier: Optical Microscopy on a Nanometric Scale

Abstract

In near-field scanning optical microscopy, a light source or detector with dimensions less than the wavelength (λ) is placed in close proximity (λ/50) to a sample to generate images with resolution better than the diffraction limit. A near-field probe has been developed that yields a resolution of ∼12 nm (∼λ/43) and signals ∼10⁴- to 10⁶-fold larger than those reported previously. In addition, image contrast is demonstrated to be highly polarization dependent. With these probes, near-field microscopy appears poised to fulfill its promise by combining the power of optical characterization methods with nanometric spatial resolution.