Abstract: Disclosed are MEMS-based optical image scanners and methods for imaging using the same. According to one embodiment, a 3-D scanner for endoscopic imaging is provided, which includes a MEMS mirror for 1-D or 2-D lateral scanning and a MEMS lens for scanning along the optical axis to control the focal depth. The MEMS lens can be a microlens bonded to a MEMS holder. Both the MEMS holder and the MEMS mirror can be electrothermally actuated. A single-mode fiber can be used for both delivering the light to and receiving the returning light from an object being examined.