A high-reflectivity electromagnetic two-axis microscanner is presented, which uses dielectric multi-layer coating on the aluminum film at the reflective surface. The microscanner is driven biaxially with the torque generated between the radially directed magnetic field and the current path through a single-turn copper coil patterned on the scanner. To enhance reflectivity, dielectric multi-layers of Al2O3 and TiO2 films are coated on the aluminum reflective surface of the mirror. A reflectance of 96.31% was obtained by using two pairs of dielectric films at a wavelength of 850 nm. Laser irradiation tests were performed to measure the operational reliability of the microscanner. The temporal drift of the optical scan angle for the mirror with two pairs of dielectric layers was measured to be 0.16° during a 6-h operation using a femtosecond pulsed laser irradiation with an average power of 2.3 W and a high repetition rate of 80 MHz. However, for the mirror where the reflection surface was coated with an aluminum layer only, a 1.74° degradation of the tilting angle was observed.
Bibliographical noteFunding Information:
Funding: This research was supported by the Space Core Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT ( NRF-2013M1A3A3A02042410 ) and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT ( NRF-2017R1A2B4007830 ). Haesoo Jeong received the BS degree from the department of electronics and electrical engineering at the Dankook University, Korea, in 2015. Currently he is in his MS degree program in the department of electronics and electrical engineering at the Dankook University. His research interests include the design and fabrication of multilayer stack coating on scanning micromirror to endure high power laser for the application to the LIDAR system. Chang-Hyeon Ji received the B.S. and M.S. degrees in electrical engineering and the Ph.D. degree in electrical engineering and computer science from Seoul National University, Seoul, Korea, in 1995, 1997, and 2001, respectively. His doctoral dissertation concerned the design, fabrication, and testing of electromagnetic micromirrors for microphotonic applications. He was with the LG Electronics Institute of Technology, Seoul, from 2001 to 2006 as a Senior and Chief Research Engineer, where he developed microactuators for various types of applications, including optical communication and raster scanning laser display system. From 2006 to 2011, he was a Postdoctoral Fellow at the Georgia Institute of Technology, Atlanta, where he researched micro power generators and energy harvesters, through-wafer interconnection technology for integrated power electronics, and microfabricated components for wireless power transfer and energy storage. In 2011, he joined the faculty of the Department of Electronics Engineering, Ewha Womans University, Seoul, where he is currently working as an Associate Professor. His current research interests include power microelectromechanical systems (MEMS), bio-MEMS, optical MEMS and nanofabrication technology. Seung-Ki Lee received the BS, MS, and PhD degrees in electrical engineering from Seoul National University, Seoul, Korea, in 1986, 1988, and 1992, respectively. His graduate research concentrated on design, fabrication, and characterization of silicon magnetotransistor. From 1992 to 1993, he was a JSPS Fellow with Tohoku University, Sendai, Japan, where he was involved in research on linear silicon microactuators using microelectromechanical system technology. In 1994, he joined the faculty of the department of electrical engineering, Dankook University, Seoul, where he is currently a professor with the department of electronics and electrical engineering. From 2003 to 2004, he was a visiting professor with the Center for Intelligent Materials and Systems, University of Washington, Seattle, where he was involved in research on surface plasmon resonance (SPR) biosensors. He has conducted extensive research on medical applications of shape memory alloy actuators and electroactive polymers, biosensors using SPR, and microbial fuel cells using single cells. Jae-Hyoung Park received the B.S., M.S., and Ph.D. degrees in electrical engineering from Seoul National University (SNU), Seoul, Korea, in 1997, 1999, and 2002, respectively. He was a Research Staff Member with the Center for 3-D Millimeter-Wave Integrated Systems, SNU, from 2002 to 2004. He was with the Microsystem Group, LG Electronic Institute of Technology, as a Chief Research Engineer, from 2004 to 2006. From 2006 to 2009, he was a Full Time Instructor with the Department of Physics, Ewha Womans University, Seoul. In 2009, he joined Dankook University, Gyeonggi-do, Korea, where he is currently a Faculty Member with the Department of Electronics and Electrical Engineering. Currently, his research interest focuses on developing scanning micromirror for the LIDAR system and exploring mirotip electrode array for electrochemical sensors and bio applications.
© 2018 Elsevier B.V.
- Dielectric multi-layer
- High reflectivity
- Pulsed laser irradiation
- Two-axis microscanner