Efficient optimization of super-oscillatory lens and transfer function analysis in confocal scanning microscopy

Abstract Super-oscillatory lens (SOL) provides a promising way to achieve subwavelength focusing in the regime of far-field optics and realize super-resolution imaging in confocal scanning microscopy (CSM). Both binary amplitude and phase SOLs are designed with an efficient optimization method using genetic algorithm and fast Hankel transform algorithm either in oil immersion medium or in air. A much brighter hotspot is readily focused by a phase SOL compared with the amplitude counterpart, e.g., 5.8 times as bright as the latter. To fundamentally interpret the super-resolution imaging mechanism by SOL in CSM, transfer function analysis is conducted compared with basic confocal imaging. The coherent transfer function (CTF) is derived and numerically calculated. The extension of the cutoff frequency and the remarkable enhancement of the magnitude of CTF in the high frequency passband account for super-resolution imaging by SOL in CSM; however, the limited extension of the frequency domain also implies that the attainable resolution is physically limited.

[1]  Zhaowei Liu,et al.  Superlenses to overcome the diffraction limit. , 2008, Nature materials.

[2]  Nikolay I. Zheludev,et al.  Super-oscillatory optical needle , 2013 .

[3]  M. Gu,et al.  Principles Of Three-Dimensional Imaging In Confocal Microscopes , 1996 .

[4]  T. Grosjean,et al.  Smallest focal spots , 2007 .

[5]  I. Golub,et al.  Toward the subdiffraction focusing limit of optical superresolution. , 2007, Optics letters.

[6]  J. Pendry,et al.  Negative refraction makes a perfect lens , 2000, Physical review letters.

[7]  S. J. Hewlett,et al.  Superresolution in confocal scanning microscopy. , 1991, Optics letters.

[8]  Zhaowei Liu,et al.  Focusing surface plasmons with a plasmonic lens. , 2005, Nano letters.

[9]  Mark R. Dennis,et al.  A super-oscillatory lens optical microscope for subwavelength imaging. , 2012, Nature materials.

[10]  Jiubin Tan,et al.  Vectorial design of super-oscillatory lens. , 2013, Optics express.

[11]  A. Meixner,et al.  Tighter focusing with a parabolic mirror. , 2008, Optics letters.

[12]  Pedro Andrés,et al.  Three-dimensional superresolution by annular binary filters , 1999 .

[13]  E. Ozbay.  Plasmonics: Merging Photonics and Electronics at Nanoscale Dimensions , 2006, Science.

[14]  Jiubin Tan,et al.  Rigorous theory on elliptical mirror focusing for point scanning microscopy. , 2012, Optics express.

[15]  Nikolay I Zheludev,et al.  Super-resolution without evanescent waves. , 2008, Nano letters.

[16]  Jian Liu,et al.  Spoke wheel filtering strategy for on-axis flattop shaping. , 2010, Optics express.

[17]  David E. Goldberg,et al.  Genetic Algorithms in Search Optimization and Machine Learning , 1988 .

[18]  Jiubin Tan,et al.  Modulation of a super-Gaussian optical needle with high-NA Fresnel zone plate. , 2013, Optics letters.

[19]  G. Toraldo di Francia,et al.  Super-gain antennas and optical resolving power , 1952 .

[20]  Tao Liu,et al.  Tighter focusing of amplitude modulated radially polarized vector beams in ultra-high numerical aperture lens systems , 2013 .

[21]  A. Siegman.  Quasi fast Hankel transform. , 1977, Optics letters.

[22]  G Leuchs,et al.  Sharper focus for a radially polarized light beam. , 2003, Physical review letters.

[23]  J. Goodman.  Introduction to Fourier optics , 1969 .