title: Synthetic aperture microscopy based on referenceless phase retrieval with an electrically tunable lens.
abstract: Phase imaging microscopy, based either on holography or nonholographic methods such as phase retrieval, has seen considerable attention recently. Phase retrieval offers the advantage of being free of a reference arm and enables a more stable and compact setup. We present an optical setup that provides enhanced resolution by implementing synthetic aperture imaging based on phase retrieval using an electrically tunable lens (ETL). The ETL is a more compact and less expensive alternative to computerized translation stages and spatial light modulators. Before applying phase retrieval, we discuss a general calibration algorithm, which performs image registration, corrects for magnifications, and determines the axial locations of image planes. Finally, we obtain resolution-enhanced images of a phase grating and of cells to demonstrate the practical application of our technique.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Lee
authors.forename: Kyunghun
authors.initials: K
authors.lastname: Han
authors.forename: Hyeon Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Weiner
mesh_terms: D000465:Algorithms; D002138:Calibration; D004867:Equipment Design; D057809:HEK293 Cells; D006696:Holography / Q000379:methods; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007909:Lenses; D008027:Light; D008853:Microscopy / Q000379:methods*; D055095:Optics and Photonics / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013314:Stress, Mechanical