title: Vectorial modeling of near-field imaging with uncoated fiber probes: transfer function and resolving power.
abstract: Using exact 3D vectorial simulations of radiation coupling into uncoated dielectric fiber probes, we calculate amplitude transfer functions for conical single-mode fiber tips at the light wavelength of 633 nm. The coupling efficiency of glass fiber tips is determined in a wide range of spatial frequencies of the incident radiation for opening angles varying from 30 degrees to 120 degrees . The resolution in near-field imaging with these tips is considered for field distributions limited in both direct and spatial-frequency space. The characteristics of the transfer functions describing the relation between probed optical fields and near-field images are analyzed in detail. The importance of utilizing a perfectly sharp tip is also examined.
authors.affiliation: Department of Communications, Optics and Materials, Nano-DTU, Technical University of Denmark, Kongens Lyngby, Denmark. ngr@com.dtu.uk
authors.forename: Niels
authors.initials: N
authors.lastname: Gregersen
authors.forename: Bjarne
authors.initials: B
authors.lastname: Tromborg
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Bozhevolnyi
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods*; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity