title: Reflective Fourier ptychography.
abstract: The Fourier ptychography technique in reflection mode has great potential applications in tissue imaging and optical inspection, but the current configuration either has a limitation on cut-off frequency or is not practical. By placing the imaging aperture stop outside the illumination path, the illumination numerical aperture (NA) can be greater than the imaging NA of the objective lens. Thus, the cut-off frequency achieved in the proposed optical system is greater than twice the objective's NA divided by the wavelength (2NAobj/λ ), which is the diffraction limit for the cut-off frequency in an incoherent epi-illumination configuration. We experimentally demonstrated that the synthesized NA is increased by a factor of 4.5 using the proposed optical concept. The key advantage of the proposed system is that it can achieve high-resolution imaging over a large field of view with a simple objective. It will have a great potential for applications in endoscopy, biomedical imaging, surface metrology, and industrial inspection.
authors.affiliation: University of Arizona, College of Optical Sciences, 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Shaun
authors.initials: S
authors.lastname: Pacheco
authors.affiliation: University of Connecticut, Biomedical Engineering, 260 Glenbrook Road, Storrs, Connecticut 06269, United StatescUniversity of Connecticut, Electrical and Computer Engineering, 371 Fairfield Way, Storrs, Connecticut 06269, United States.
authors.forename: Guoan
authors.initials: G
authors.lastname: Zheng
authors.affiliation: University of Arizona, College of Optical Sciences, 1630 East University Boulevard, Tucson, Arizona 85721, United States.
authors.forename: Rongguang
authors.initials: R
authors.lastname: Liang
mesh_terms: D000818:Animals; D002645:Chickens; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005583:Fourier Analysis; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D008962:Models, Theoretical; D018482:Muscle, Skeletal / Q000737:chemistry; D055095:Optics and Photonics / Q000295:instrumentation