OBSERVATION OF SUBCELLULAR STRUCTURES OF NEURONS BY AN ILLUMINATION MODE NEAR-FIELD OPTICAL MICROSCOPE UNDER AN OPTICAL FEEDBACK-CONTROL

We propose an illumination mode near-field optical microscope operated under an optical feedback for imaging biological specimens in their n atural environment. For feedback control, rapidly varying evanescent s ignal has been generated over the sample surface. It has been found th at evanescent signal can be probably used as a control signal by utili zing its sample feature dependent discrimination sensitivity. Neurons have been successfully observed both in air and in liquid with a resol ution well beyond the diffraction limit.