A micromirror array with annular partitioning for high-speed random-access axial focusing  

作　　者：Nathan Tessema Ersumo Cem Yalcin Nick Antipa Nicolas Pegard Laura Waller Daniel Lopez Rikky Muller 

机构地区：[1]The University of California,Berkeley and University of California,San Francisco Graduate Program in Bioengineering,Berkeley,CA 94720,USA [2]Department of Electrical Engineering&Computer Sciences,University of California,Berkeley,CA 94720,USA [3]Department of Applied Physical Sciences,University of North Carolina at Chapel Hill,Chapel Hill,NC 27514,USA [4]Chan Zuckerberg Biohub,San Francisco,CA 94158,USA [5]Physical Measurement Laboratory,National Institute of Standards and Technology,Gaithersburg,MD 20899,USA

出　　处：《Light(Science & Applications)》2020年第1期241-255,共15页光（科学与应用)（英文版）

基　　金：the McKnight Technological Innovations in Neuroscience Award as well as the Burroughs Wellcome Fund Career Award At the Scientific Interface(5113244)to N.P;supported by the U.S.Department of Energy,Office of Science,under Contract No.DE-AC02-06CH11357.

摘　　要：Dynamic axial focusing functionality has recently experienced widespread incorporation in microscopy,augmented/virtual reality(AR/VR),adaptive optics and material processing.However,the limitations of existing varifocal tools continue to beset the performance capabilities and operating overhead of the optical systems that mobilize such functionality.The varifocal tools that are the least burdensome to operate(e.g.liquid crystal,elastomeric or optofluidic lenses)suffer from low(≈100 Hz)refresh rates.Conversely,the fastest devices sacrifice either critical capabilities such as their dwelling capacity(e.g.acoustic gradient lenses or monolithic micromechanical mirrors)or low operating overhead(e.g.deformable mirrors).Here,we present a general-purpose random-access axial focusing device that bridges these previously conflicting features of high speed,dwelling capacity and lightweight drive by employing lowrigidity micromirrors that exploit the robustness of defocusing phase profiles.Geometrically,the device consists of an 8.2mm diameter array of piston-motion and 48-μm-pitch micromirror pixels that provide 2πphase shifting for wavelengths shorter than 1100 nm with 10-90% settling in 64.8μs(i.e.,15.44 kHz refresh rate).The pixels are electrically partitioned into 32 rings for a driving scheme that enables phase-wrapped operation with circular symmetry and requires<30 V per channel.Optical experiments demonstrated the array’s wide focusing range with a measured ability to target 29 distinct resolvable depth planes.Overall,the features of the proposed array offer the potential for compact,straightforward methods of tackling bottlenecked applications,including high-throughput single-cell targeting in neurobiology and the delivery of dense 3D visual information in AR/VR.

关 键 词：MIRROR AXIAL RANDOM 

分 类 号：O43[机械工程—光学工程]