面向超分辨光学成像的浸没微球透镜控制

Images with resolution beyond the diffraction limit can be achieved by combining conventional microscopy with a microsphere. In order to position the microsphere on the field of interest of the sample surface and to expand the observation area, a method to manipulate the microsphere by combining it with a multi-axis translation stage was proposed in this paper. Images were obtained by scanning the microsphere, which was positioned accurately by driving the translation stage with four degrees of freedom. The influence of the probe on the super-resolution image was analyzed by performing an optical simulation. Kinematic analysis of the translation stage was studied for determining the manipulation strategy of the microsphere. Force analysis of the microsphere in a liquid medium was carried out to evaluate the possibility of detachment of the microsphere from the probe. By using a microsphere, the gap between the Blu-ray disc stripes could be clearly observed. The experimental results indicate that the amplification factor of the microsphere is 3.52 and a resolution of 130 nm (approximately λ/4) can be achieved. In addition, by scanning the microsphere along the S-shaped trajectory at a speed of 5×10^-6 m/s over the sample surface, the super-resolution image over a large continuous area was achieved. Therefore, by using this method, the imaging area could be expanded and the observation efficiency was improved.