Papers by Author: Guo Fan Jin

Abstract: Microscopy is an important tool in biology and medicine, but it is often limited to optical imaging structures with high numerical aperture(NA) with a short working distance(wd), for example NA = 0.6 and wd <1 mm are usual. The common microscope objective is inadequate for imaging of living cells in culture as an optical imaging structure with both high numerical aperture and long working distance is required. In this study, a novel optical design has been developed to meet the long working distance and high resolution power imaging of living cells in a vessel with a high culture solution thickness, where cells need to be developed in about 48 hours or a week. The developed optical design was characterized by an ultra-long working distance (wd >13.5 mm) and high numerical aperture (NA = 0.7). This optical imaging system is not only good for the subcellular imaging of free-floating cells in culture, but also for the imaging of cells attached at a surface of vessel.

Abstract: NURBS surface representation, combined with Differential Evolution (DE), enables us to perform automated non-imaging reflector design. The overall result is a simple automated nonimaging reflector design technique and only a little data such as desired illuminance distribution and searching limits are needed. Merit functions specific to non-imaging reflector design are presented. Using different merit functions, the generated illuminance distribution can be uniform as well as concentrated. DE is performed to obtain the reflector that generates the desired illuminance distribution. The photometric distributions are calculated through Monte-Carlo ray tracing and the illuminance value is used to calculate the merit function value. The validity of the proposed approach is demonstrated by optimization examples. Almost the same uniform illuminance distribution can be obtained using the algorithm proposed in this paper as that obtained by edge-raymethod. A concentrated illuminance distribution can also be generated using the algorithm proposed.