Characteristics of periodically domain-inverted LiNbO3 and LiTaO3 waveguides for second harmonic generation

Characteristics of waveguides with periodically domain‐inverted regions in LiNbO3 and LiTaO3 for quasi‐phase‐matched (QPM) second harmonic generation are investigated. The domain‐inverted regions in LiNbO3 are formed by heat treatment using selective SiO2 mask and those in LiTaO3 are formed by heat treatment using selective proton exchange. The domain‐inverted region in LiTaO3 is fabricated up to 2.7 μm depth, which is twice as deep as that in LiNbO3. The channel waveguides incorporating the regions are fabricated using proton exchange by pyrophosphoric acid. The propagation loss (0.9 dB/cm) of LiTaO3 waveguide is much lower than that of LiNbO3 waveguide (2.9 dB/cm). The second harmonic power generated in LiTaO3 waveguide by third‐order QPM consequently has three time higher conversion efficiency, compared to that in LiNbO3 waveguide. In domain‐inverted LiNbO3 waveguide, we have observed optical damage. On the other hand, in domain‐inverted LiTaO3 waveguide, stable blue light (421 nm) has been obtained wi...

[1]  Duan Feng,et al.  Enhancement of second‐harmonic generation in LiNbO3 crystals with periodic laminar ferroelectric domains , 1980 .

[2]  A. Yariv,et al.  Phase matching by periodic modulation of the nonlinear optical properties , 1972 .

[3]  K. Tada,et al.  Electrooptic Coefficient r33 in Proton-Exchanged z-Cut LiTaO3 Waveguides , 1989 .

[4]  M. Fejer,et al.  Quasi‐phase‐matched second‐harmonic generation of blue light in periodically poled LiNbO3 , 1990 .

[5]  G. D. Boyd,et al.  OPTICALLY‐INDUCED REFRACTIVE INDEX INHOMOGENEITIES IN LiNbO3 AND LiTaO3 , 1966 .

[6]  Gregory L. Tangonan,et al.  High optical power capabilities of Ti‐diffused LiTaO3 waveguide modulator structures , 1977 .

[7]  W. J. Kozlovsky,et al.  Blue light generation by frequency doubling in periodically poled lithium niobate channel waveguide , 1989 .

[8]  S. Sato,et al.  Wavelength dependence of photorefractive effect in Ti‐indiffused LiNbO3 waveguides , 1989 .

[9]  J. Veselka,et al.  Proton exchange for high‐index waveguides in LiNbO3 , 1982 .

[10]  S. Colak,et al.  Efficient type I blue second‐harmonic generation in periodically segmented KTiOPO4 waveguides , 1990 .

[11]  N. Bloembergen,et al.  Interactions between light waves in a nonlinear dielectric , 1962 .

[12]  Ferroelectric inversion layers formed by heat treatment of proton‐exchanged LiTaO3 , 1990 .

[13]  F. Duan,et al.  Study of LiTa03 crystals grown with a modulated structure I. Second harmonic generation in LiTa03 crystals with periodic laminar ferroelectric domains , 1986 .

[14]  F. Laurell,et al.  Blue light generated by frequency doubling of laser diode light in a lithium niobate channel waveguide , 1989, IEEE Photonics Technology Letters.