A new class of flat, ultrathin optical devices on a chip was developed by scientists from the Center for Nanoscale Materials at Argonne National Laboratory and Harvard University. The new design uses a microscopic electromechanical device (MEMS) as a platform. The design imparts dynamic and high-speed control to an optical lens for actively steering light.
The ultrathin lenses, with their ability to mold and shape light, can potentially replace bulky traditional curved lenses. Adding active control to this new class of nanostructures will greatly expand their function in optical technologies and overcome their static nature.
An optical metasurface is a designer interface that packs together multiple materials carefully selected for their ability to control light. The resulting nanoscale surface can fold and shape light to create a variety of flat optical components. The researchers' prototype uses a micro-electromechanical system (MEMS) to bring active control to the static metasurface lens. The device, a 2-D scanner micro-mirror, focuses light in a range that is common to many optical applications. When triggered electronically, the MEMS platform steers the angle of the lens along two axes and scans the focal spot in each direction. The team fabricated the device using standard computer-chip technology and fused the flat lens onto the MEMS with platinum patches. This method enables integration of other hybrid structures of varying dimensions. The new dynamic metasurface lens has potential across wider fields, such as MEMS-based microscope systems and holographic and projection imaging. The researchers foresee designs with thousands of individually controlled devices onto a single silicon chip that would lead to an unprecedented degree of control and manipulation of the optical field.
Argonne National Laboratory
The Air Force Office of Scientific Research and the National Science Scholarship from A *STAR, Singapore (S. Zhang) provided funding. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation. CNS is part of Harvard University. Use of the scientific user facility Center for Nanoscale Materials was supported by the Department of Energy, Office of Science, Office of Basic Energy Sciences.
T. Roy, S. Zhang, W. Jung, M. Troccoli, et al., "Dynamic metasurface lens based on MEMS technology." APL Photonics 3, 2 (2018). [DOI 10.1063/1.5018865]
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