title: Compact multi-band fluorescent microscope with an electrically tunable lens for autofocusing.
abstract: Autofocusing is a routine technique in redressing focus drift that occurs in time-lapse microscopic image acquisition. To date, most automatic microscopes are designed on the distance detection scheme to fulfill the autofocusing operation, which may suffer from the low contrast of the reflected signal due to the refractive index mismatch at the water/glass interface. To achieve high autofocusing speed with minimal motion artifacts, we developed a compact multi-band fluorescent microscope with an electrically tunable lens (ETL) device for autofocusing. A modified searching algorithm based on equidistant scanning and curve fitting is proposed, which no longer requires a single-peak focus curve and then efficiently restrains the impact of external disturbance. This technique enables us to achieve an autofocusing time of down to 170 ms and the reproductivity of over 97%. The imaging head of the microscope has dimensions of 12 cm × 12 cm × 6 cm. This portable instrument can easily fit inside standard incubators for real-time imaging of living specimens.
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China ; leiming@opt.ac.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China ; yaobl@opt.ac.cn.
authors.forename: Baoli
authors.initials: B
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China.
authors.forename: Yansheng
authors.initials: Y
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119, China.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
authors.forename: Xibin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China.
authors.forename: Daxi
authors.initials: D
authors.lastname: Xiong
keywords: (110.0110) Imaging systems; (110.0180) Microscopy; (180.2520) Fluorescence microscopy