DESING OF A MODEL OMMATIDIUM OF BEIJING FIREFLY COMPOUND EYE AND STUDIED BY RAY TRACING
北京萤火虫复眼的模型小眼设计与光线追迹

ased on the parameters of real structure and physiology of Beijing firefly's compound eye, an analogue of the dioptric system of an ommetidium was established. In the model a parabolic profile formula of refractive index was sued in the radial GRIN lens cylinder; the radical graded and longifudinal graded refractive index distribution formula was used in the GRJN lens hemieliposid region of proximal crystalline cone.According to the results of ray tracing, it wu proved that the model ommatidium is approximatily a tolescope system; when palalled light rays enter this lens sytem, they go in paralled away from it. The comeal lens and the distal part of the cpetalljne cone from the first component of the model ommatidium focus parallel incident rays together to the infocus. The focus is just the distal to the waist in the crystalline cone. These rays emerge from the cone tip in parallel after it pareing through the proximal crystalline cone. The model ommatidium set a maximum incidence angle, that is 30 degrees. Within that maximuse incidence angle, the angular maginification M is approximately the same for all angles of incidence. The larger the angle of incidence of a palallel beam of light on an ommatidium is, the further the intermediate image lies from the cone axis.