In 2000, the authors developed an image sensor and a video camera of 1,000,000 fps. The image sensor was an in-situ storage image sensor (ISIS) with slanted linear CCD storage. Possible structures for the next-generation ISIS are discussed. A backside-illuminated ISIS is one of the promising structures.
A novel wave optical simulation method (a localized boundary element method) has been developed. This method enables us to execute 3-D wave optical simulation with much smaller memory space and much shorter calculation time than conventional boundary element methods or FDTD(Finite Difference Time Domain) methods. The color shading characteristics of inner lens structures in CCD image sensors and the light-gathering power and crosstalk of light waveguide structures in CMOS image sensors can be analyzed by this method. This method was found to be powerful and useful for wave optical analysis of image sensors.