title: Super-resolution bright-field optical microscopy based on nanometer topographic contrast.
abstract: By using an expectation-maximization maximum likelihood estimation algorithm to improve the lateral resolution of a recently developed non-interferometric wide-field optical profilometer, we obtain super-resolution bright-field optical images of nanometer features on a flat surface. The optical profilometer employs a 365-nm light source and an ordinary objective lens of a 0.95 numerical aperture. For objects of 100 nm thickness, lateral features about lambda/7 can be resolved in the restored images without fluorescence labeling. Current image acquisition rate is 0.1 frame/sec, which is limited by the brightness of the light source. With a brighter light source, the imaging speed can be fast enough for real-time observation of dynamic activities in the nanometer scale.
authors.affiliation: Department of Electrical Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Shu-Wei
authors.initials: SW
authors.lastname: Huang
authors.forename: Hong-Yao
authors.initials: HY
authors.lastname: Mong
authors.forename: Chau-Hwang
authors.initials: CH
authors.lastname: Lee
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D008857:Microscopy, Interference; D036103:Nanotechnology; D055095:Optics and Photonics