Heterogeneous integration of micro-opto-electromechanical systems (MOEMS) and integrated circuits (ICs) allows the combination of high-quality optical and photonic MOEMS materials such as monocrystalline silicon (Si) with standard CMOS-based electronic circuits in order to realize complex optical systems. In this paper, we will present examples of such heterogeneous optical systems, including CMO-Sintegrated SiGe bolometer arrays and CMOS-integrated Si micro-mirror arrays.