Optical characterization methods for solid-state image sensors

The accurate measurement of the optoelectronic properties of imaging sensor s is of utmost importance for their appropriate use in various modern appli cation fields. such as in metrology, quality control. environmental monitor ing, medicine or for automotive applications. Key sensor parameters include spatial resolution. uniformity, sensitivity. linearity, signal to noise ra tio and dynamic range. Today high-end optical systems mostly rely on charge coupled device (CCD) image sensors. Continuous progresses in CMOS submicro n technology and the advent of 'active pixel sensor' (APS) imagers have how ever led to a wealth of novel line and area array imaging devices with adde d functionalities (eg. on-chip control and readout electronics) or performa nce optimized for specific tasks (eg. a dynamic range in excess of 120dB). The optimal use of CMOS image sensing technology nevertheless depends stron gly on the absolute and accurate optoelectronic characterization of these d evices. Modern measurement techniques for a reliable, traceable, precise an d absolute measurement of the most relevant parameters of CCD and CMOS imag ing sensors are described and discussed in the present paper, with examples based on recent state-of-the art CMOS imagers. (C) 2001 Elsevier Science L td. All rights reserved.