A new method of Q factor optimization by introducing two nodal wedges in a tuning-fork/fiber probe distance sensor.

We report on a new method of achieving and optimizing a high Q factor in a near-field scanning optical microscope (NSOM) by introducing two nodal wedges to a tuning-fork/fiber probe distance sensor and by selecting a vibrational mode of the dithering sensor. The effect of the nodal wedges on the dynamical properties of the sensor is theoretically analyzed and experimentally confirmed. The optimization achieved by the proposed method is understood from the vibration isolation and the subsequent formation of a local vibration cavity. The optimal condition is found to be less susceptible to the variation of the fiber tip length. This method allows effective NSOM measurement of samples placed even in aqueous solution.

[1]  V. Letokhov,et al.  Double-resonance probe for near-field scanning optical microscopy , 2006 .

[2]  Majed Chergui,et al.  Q-factor optimization of a tuning-fork/fiber sensor for shear-force detection , 2005 .

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

[4]  Cagatay Basdogan,et al.  Adaptive Q control for tapping-mode nanoscanning using a piezoactuated bimorph probe. , 2007, The Review of scientific instruments.

[5]  M. Miles,et al.  High-Q dynamic force microscopy in liquid and its application to living cells. , 2001, Biophysical journal.

[6]  Cagatay Basdogan,et al.  State feedback control for adjusting the dynamic behavior of a piezoactuated bimorph atomic force microscopy probe. , 2009, The Review of scientific instruments.

[7]  L. Novotný,et al.  Imaging of membrane proteins using antenna-based optical microscopy , 2008, Nanotechnology.

[8]  H. Hölscher,et al.  Increasing the Q factor in the constant-excitation mode of frequency-modulation atomic force microscopy in liquid , 2006 .

[9]  Christopher C. Davis,et al.  A phase-locked shear-force microscope for distance regulation in near-field optical microscopy , 1997 .

[10]  Tadashi Mitsui,et al.  Development of a polarization-preserving optical-fiber probe for near-field scanning optical microscopy and the influences of bending and squeezing on the polarization properties , 2005 .

[11]  Manhee Lee,et al.  Active Q control in tuning-fork-based atomic force microscopy , 2007 .

[12]  N. F. van Hulst,et al.  Shear force imaging of soft samples in liquid using a diving bell concept , 2003 .

[13]  Levi A. Gheber,et al.  Design and optimization of a near-field scanning optical microscope for imaging biological samples in liquid. , 1998, Applied optics.

[14]  A. L. Rosa,et al.  The ultrasonic/shear-force microscope: Integrating ultrasonic sensing into a near-field scanning optical microscope , 2005 .

[15]  S.J.B. Yoo,et al.  Electrical subharmonic hybrid mode locking of a colliding pulse mode-locked laser at 28 GHz , 2005, IEEE Photonics Technology Letters.