Waveguide structures are fabricated in z-cut LiNbO3 using focused femtosecond laser pulses.Microstructural modifications were investigated by means of the optical microscopy.And the near-field intensity distributions at 633 nm of the waveguide′s modes were obtained.The results show that the guiding occurs in a material modification region created at the focus.And the waveguide modes were demonstrated under TE and TM polarizations.The effects of scanning speed and laser energy on the optical wave...