A laser test system for characterizing CMOS active pixel sensors

CMOS active pixel sensor suitability for radiation detection purposes has been already demonstrated. In particular, the adoption of a fully standard deep sub-micron CMOS technology allows to obtain a very compact pixel size, an efficient integration of smart electronics and ease of porting to future, more advanced, technology nodes. These characteristics potentially enhance the sensor capabilities, in terms of spatial resolution and energy resolution. In order to verify such hypotheses, test chips have been fabricated, and a dedicated laser test bench has been devised and implemented. The test bench features a mechanical movement section with sub-micron positioning capabilities, and an optic axis with a beam-splitter that allows the fine focalization of a near infrared laser stimulus and also to obtain a visible picture to control the irradiated region. A low-cost comprehensive active pixel sensor characterization can be therefore carried out as an alternative to more expensive beam test characterizations.