We have experimentally demonstrated that the resolution of a commercial two-photon microscope is improved using a ${\text{TM}}_{01}$ laser beam. With a water immersion objective having a 1.2 NA, the measured point- spread function has an area of $0.15{\lambda }^2$ . We used a plane interface between dielectrics instead of an annular aperture to increase the relative contribution of the longitudinal field of the ${\text{TM}}_{01}$ laser beam. The results are in agreement with the vectorial diffraction theory established by Richards and Wolf [ Proc. R. Soc. Lond. A 253, 358 (1959) ]. The ${\text{TM}}_{01}$ laser beam was produced with a quadrant of half-wave plates. We have also used the same mode converter to generate a ${\text{TE}}_{01}$ laser beam with a zero at the beam center.