The research objective of this proposal is to develop a near-field scanning optical microscope (NSOM) for biological research. NSOM is a form of microscopy that is not diffraction limited in resolution, as are confocal and conventional optical microscopes. Although NSOM allows for super-resolution (less than 100nm at visible wavelengths), technical difficulties remain in order to be able to achieve this resolution in living biological samples. The major difficulty has been that the scanned NSOM probe which produces a spot as small as 50nm in diameter must stay within 10-20nm of the surface of the sample being imaged. The method works well for """"""""hard"""""""" samples, but relies on probe-sample forces to keep the distance regulation and these forces tend to de form soft biological samples being imaged. The proposed research will solve that problem by using an all optical feedback method, called laser feedback, to maintain the probe-sample distance regulation during non-invasive imaging. Laser feedback can optically detect with atomic precision surfaces with minimal reflectance. Successful application of this method will allow the NSOM method to non-invasively image biological samples and generate accurate super-resolution images.
| Reitz, Frederick B; Fauver, Mark E; Pollack, Gerald H (2002) Fluorescence anisotropy near-field scanning optical microscopy (FANSOM): a new technique for nanoscale microviscometry. Ultramicroscopy 90:259-64 |
