Enhanced resolution in two-photon imaging using a TM(01) laser beam at a dielectric interface

Opt Lett. 2009 Dec 1;34(23):3601-3. doi: 10.1364/OL.34.003601.


We have experimentally demonstrated that the resolution of a commercial two-photon microscope is improved using a TM(01) laser beam. With a water immersion objective having a 1.2 NA, the measured point- spread function has an area of 0.15lambda(2). We used a plane interface between dielectrics instead of an annular aperture to increase the relative contribution of the longitudinal field of the TM(01) laser beam. The results are in agreement with the vectorial diffraction theory established by Richards and Wolf [Proc. R. Soc. Lond. A253, 358 (1959)]. The TM(01) laser beam was produced with a quadrant of half-wave plates. We have also used the same mode converter to generate a TE(01) laser beam with a zero at the beam center.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air
  • Electric Impedance
  • Glass
  • Lasers*
  • Models, Theoretical
  • Molecular Imaging
  • Photons*