title: Comprehensive study of unexpected microscope condensers formed in sample arrangements commonly used in optical microscopy.
abstract: We show that various setups for optical microscopy which are commonly used in biomedical laboratories behave like efficient microscope condensers that are responsible for observed subwavelength resolution. We present a series of experiments and simulations that reveal how inclined illumination from such unexpected condensers occurs when the sample is perpendicularly illuminated by a microscope's built-in white-light source. In addition, we demonstrate an inexpensive add-on optical module that serves as an efficient and lightweight microscope condenser. Using such add-on optical module in combination with a low-numerical-aperture objective lens and Fourier plane imaging microscopy technique, we demonstrate detection of photonic crystals with a period nearly eight times smaller than the Rayleigh resolution limit.
authors.forename: Darshan B
authors.initials: DB
authors.lastname: Desai
authors.forename: Mabkhoot Mudith S
authors.initials: MM
authors.lastname: Aldawsari
authors.forename: Bandar Mohammed H
authors.initials: BM
authors.lastname: Alharbi
authors.forename: Sanchari
authors.initials: S
authors.lastname: Sen
authors.forename: Luis
authors.initials: L
authors.lastname: Grave de Peralta
mesh_terms: D002857:Chromium / Q000737:chemistry; D003460:Crystallization; D004867:Equipment Design; D007909:Lenses; D008027:Light; D008029:Lighting; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods*; D055095:Optics and Photonics / Q000379:methods*; D010781:Photography / Q000379:methods; D017785:Photons; D012542:Scattering, Radiation
chemical_list: D002857:Chromium