Aperture-size-controlled optical fiber tips for high-resolution optical microscopy

A method is developed to produce chemically etched optical tips for near-field and confocal microscopies with valuable properties such as large transmission and no lateral light leaks. Prior to metal coating, tips are coated with a dielectric material, MgF2, that is refraction-index-matched to silica. It is shown that adjusting the MgF2 layer thickness allows us to control the tip aperture size in the diameter range from 70to500nm. First, near-field fluorescence imaging of latex nanospheres with the smallest optical aperture tips confirms their ability to reach subwavelength optical resolution. In addition, thanks to their high transmission and collection efficiencies as well as their natural achromatism, it is proposed that the large optical aperture tips be advantageously substituted to high numerical aperture objectives in some confocal microscopes operating in constrained environments such as at low temperature.

[1]  H. Fuchs,et al.  Simultaneous topographical and optical characterization of near-field optical aperture probes by way of imaging fluorescent nanospheres , 2002 .

[2]  Volker Deckert,et al.  High-quality near-field optical probes by tube etching , 1999 .

[3]  Khaled Karrai,et al.  Far field characterization of diffracting circular apertures , 1995 .

[4]  W. Denk,et al.  Optical stethoscopy: Image recording with resolution λ/20 , 1984 .

[5]  Jorge Morgado,et al.  Near-field optical lithography of a conjugated polymer , 2003 .

[6]  Gerard Wysocki,et al.  Near-field optical nanopatterning of crystalline silicon , 2004 .

[7]  S. Huant,et al.  CdSe single-nanoparticle based active tips for near-field optical microscopy , 2005, physics/0612208.

[8]  Y. Aoyagi,et al.  Near-field optical mapping of exciton wave functions in a GaAs quantum dot. , 2003, Physical review letters.

[9]  N. F. Hulst,et al.  High definition aperture probes for near-field optical microscopy fabricated by focused ion beam milling , 1998 .

[10]  K. Karrai,et al.  Piezoelectric tip‐sample distance control for near field optical microscopes , 1995 .

[11]  S. Huant,et al.  Extension of Bethe's diffraction model to conical geometry: Application to near-field optics , 2001, 1002.0951.

[12]  P. Petroff,et al.  Stark-shift modulation absorption spectroscopy of single quantum dots , 2003 .

[13]  S. Huant,et al.  The optical near-field of an aperture tip , 2004, physics/0701034.

[14]  M. Pfeffer,et al.  Chemically etched fiber tips for near-field optical microscopy: a process for smoother tips. , 1998, Applied optics.

[15]  W. Rensen,et al.  Cell biology beyond the diffraction limit: near-field scanning optical microscopy. , 2001, Journal of cell science.

[16]  J. Krogmeier,et al.  Hybrid near-field scanning optical microscopy tips for live cell measurements , 2004 .

[17]  T. D. Harris,et al.  Breaking the Diffraction Barrier: Optical Microscopy on a Nanometric Scale , 1991, Science.

[18]  G. H. Morrison,et al.  Parameter control, characterization, and optimization in the fabrication of optical fiber near-field probes. , 1995, Applied optics.

[19]  K. Nishi,et al.  Carrier–carrier interaction in single In0.5Ga0.5As quantum dots at room temperature investigated by near-field scanning optical microscope , 2003 .

[20]  Reinhard Guckenberger,et al.  High-resolution imaging of single fluorescent molecules with the optical near-field of a metal tip. , 2004, Physical review letters.