LiNbO3 thin‐film optical waveguide grown by liquid phase epitaxy and its application to second‐harmonic generation
LiNbO3 thin‐film optical waveguide grown by liquid phase epitaxy and its application to second‐harmonic generation
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液相外延生长LiNbO3薄膜光波导及其在二次谐波产生中的应用
DOI：
10.1063/1.349409
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发表时间：
1991
影响因子：
3.2
通讯作者：
M. Saitoh
中科院分区：
文献类型：
--
作者：
H. Tamada;A. Yamada;M. Saitoh
采用Li 2 O-V2 O 5助熔剂液相外延法，在掺杂5mol%MgO的Z-平板LiNbO 3衬底上生长了结晶度高、表面形貌好的LiNbO 3薄膜光波导。通过选择熔体成分，实现了X轴上小于4×10−3 A的小晶格失配、X射线摇摆曲线中11 s的小线宽和完美的镜面。在0.6328 μm波长处，不同组成的熔体的寻常折射率no不变（2.287），但在V2 O 5固定为40mol%时，通过增加熔体中Li 2 O的含量，可以使非寻常折射率ne从2.205变为2.192或更小。经600 °C、O_3退火1h后，由V引起的波长为0.5145 μm的光吸收损耗从25 dB/cm显著降低到1.6dB/cm。通过温度调谐方法观察到单极薄膜的TE 0（1.064 μm）→ TM 0（0.532 μm）的有效二次谐波产生。揭示了自极化和畴反转的机制。
LiNbO3 thin‐film optical waveguides with high crystallinity and good surface morphology have been grown on 5 mol % MgO‐doped Z‐plate LiNbO3 substrates by liquid‐phase epitaxy using Li2O‐V2O5 flux. A small lattice mismatch less than 4×10−3 A in the X axis, a small linewidth of 11s in an x‐ray rocking curve, and a perfect mirror surface are realized by choosing a melt composition. Ordinary refractive index no at a wavelength of 0.6328 μm is unchanged (2.287) with melts of different compositions, but extraordinary refractive index ne can be changed from 2.205 to 2.192 or less by increasing Li2O in the melt with V2O5 fixed at 40 mol %. The optical absorption loss at a wavelength of 0.5145 μm caused by V incorporated from the flux is significantly reduced from 25 to 1.6 dB/cm by O3 annealing for 1 h at 600 °C. Efficient second‐harmonic generation of TE0(1.064 μm) →TM0(0.532 μm) for a single‐poled film is observed by a temperature‐tuning method. The mechanism of self poling and domain inversion which were revea...