BIOLOGICAL NEAR-FIELD SCANNING OPTICAL MICROSCOPY - INSTRUMENTATION AND SAMPLE ISSUES FOR SHEAR-FORCE FEEDBACK

The current technology of near-field microscopy is limited in two impo rtant aspects: photon throughput and scan rate. In this paper we will consider the second limitation only. Furthermore, we will consider it as a function of probe-sample feedback response time and not one of lo w light level imaging; i.e. scan times are not limited by any need to integrate the optical signal. Our considerations will focus on shear-f orce feedback response times and how it places a limit on the type of biological investigations that can be accomplished.