IMAGING ACOUSTOOPTIC TUNABLE FILTER WITH 0.35-MICROMETER SPATIAL-RESOLUTION

Image blur in acousto-optic tunable filters (AOTF's) has been a persis tent problem. Here we describe the connection between transducer struc ture and image blur and experimentally measure it by using a 5-cm 12 d egrees-cut TeO2 crystal of our design. With these quantitative results , we develop an image-processing method that minimizes AOTF-related im age degradation. The combination of long crystal design and image proc essing results in substantially improved image contrast and spatial re solution relative to conventional AOTF imaging devices. We present hig h-magnification images of fluorescent actin fibers in cells in which w e obtain a resolution of approximately 0.35 mu m, representing the fir st successful use of an AOTF for ultra-high-resolution microscopy. Fur ther improvements are also predicted. (C) 1996 Optical Society of Amer ica