Cross-section tailoring of laser-written LiNbO₃ depressed-cladding waveguides for polarization modulation and improved second harmonic generation

【摘要】 We report on laser-written depressed-cladding waveguides with specially tailored elliptical cross-sections in LiNbO₃ crystals.The experimental results reveal that both polarization characteristics and propagation losses of waveguides can be effectively modulated through precise cross-section tailoring.Second harmonic generation（SHG） performance at 1030 nm demonstrates that the SHG conversion efficiency of an elliptical cross-section waveguide is higher than that of a round one.The μ-Raman spectroscopy shows that a stress field in a waveguide core may increase with the decrease in cross-section.This work provides a practical method for realizing polarization modulation and nonlinear optical improvement of depressed-cladding waveguides,having potential applications in constructing advanced integrated photonic devices.更多还原

【Abstract】 We report on laser-written depressed-cladding waveguides with specially tailored elliptical cross-sections in LiNbO₃ crystals.The experimental results reveal that both polarization characteristics and propagation losses of waveguides can be effectively modulated through precise cross-section tailoring.Second harmonic generation（SHG） performance at 1030 nm demonstrates that the SHG conversion efficiency of an elliptical cross-section waveguide is higher than that of a round one.The μ-Raman spectroscopy shows that a stress field in a waveguide core may increase with the decrease in cross-section.This work provides a practical method for realizing polarization modulation and nonlinear optical improvement of depressed-cladding waveguides,having potential applications in constructing advanced integrated photonic devices.更多还原