An optical semiconductor device and an infrared data communication apparatus eliminating a direct current component and a low frequency component included in a light signal. A method for calibrating a switched capacitor array in a SAR data converter is disclosed, which array includes a plurality of primary capacitors having a common node plate interfaced to a common node and a switched plate interfaced to a switch that is operable to be switched between first and second reference voltages. The shape of the boundary and the distortion of the flexible membrane control the optical characteristics of a lens resulting from the application and curing of a molding composition placed on the flexible membrane or to cast other items having variable shapes determined in part by the flexible membrane. An interconnect layer, which includes first and second interconnects and is connected to the gate electrodes of the CMOS device, is formed on a second interlevel dielectric film. In this manner, a new error correction code can be calculated prior to writing the data without the need to access the memory array again. The method is based on a hierarchical pattern matching to a local lattice structure that is used as a template.