Time-Resolved CMOS Image Sensors for Biomedical Applications

Abstract

This chapter presents semiconductor imaging devices using time-resolved pixel architectures that have been designed for use in biomedical applications. It focuses on time-resolved lock-in-pixel CMOS image sensors for time-gating-based imaging systems and discusses the principle and design of multi-tap lock-in pixels and biomedical applications using time-resolved CMOS image sensors for fluorescence-lifetime imaging microscopy, time-resolved near-infrared spectroscopy, time-of-flight (TOF)-based spectroscopy, and stimulated Raman spectroscopy. Time-resolved imaging for biomedical applications requires a time resolution of sub-100 picoseconds. Low-noise time-resolved imaging owing to the limited number of available signal photons is often required for biomedical applications. To obtain better range resolution in the I-TOF measurement, the authors have proposed a new I-TOF measurement technique, employing an impulse photocurrent response. The NIRS device consists of a time-resolved CMOS image sensor and a field-programmable gate array. Time-resolved imaging for biomedical applications requires a time resolution of sub-100 picoseconds.