Mode tailoring of laser written waveguides in LiNbO_3 crystals by multi-scan of femtosecond laser pulses

摘要

We report on the mode tailoring of femtosecond laser written waveguides in LiNbO3 crystals by using multiscan technique. The effects of parameters of the laser writing, i.e., pulse energy and focusing depth, on the track formation are explored for multi-line waveguides with Type I modification. The mode profiles and guiding properties of the multi-line waveguides have been investigated in details at wavelength of 632.8 nm and 1550 nm. By adjusting the laser parameters to achieve desirable modal profiling, the multi-line waveguides can support modes at telecommunication band. Our results indicate the potential applications of the on-demand multi-line waveguides in LiNbO3 crystals as novel integrated photonic devices.