A Photovoltaically Modulated MEMS Optical Scanner for Fiber Endoscope

We have developed a new SiP (system in package) style optical MEMS (microelectromechanical system) component for fiber optic endoscope that operates without using external power supply. The endoscope sensor head (5 mm in outer diameter) attached at the end of an optical fiber is designed for the use of in vivo medical diagnosis such as gastrointestinal tact or vascular vein monitor by using an infrared probe light at a 1.3-micron-wavelength. Another infrared light of at a 1.5-micron-wavelength is used in the identical optics in a WDM (wavelength division multiplex) manner to generate the drive voltage (of up to 5 V) in the package by using a collocated photovoltaic cell. This paper describes the architecture of the optical actuation system, the scanner design and fabrication. Modulation of the MEMS scanner is demonstrated using the optical modulation, by which the risk of electrocution or electromagnetic interference is avoided.