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Second-harmonic generation in a direct-bonded periodically poled LiNbO(3) buried waveguide
Optics Letters
|December 12, 2007
Summary
Researchers fabricated a periodically poled lithium niobate (LiNbO3) waveguide for efficient frequency doubling of a Nd:YAG laser. This device achieved a 4.3%W(-1) conversion efficiency for green light generation.
Area of Science:
- Materials Science
- Optoelectronics
- Nonlinear Optics
Background:
- Periodically poled lithium niobate (PPLN) waveguides are crucial for nonlinear optical applications.
- Efficient frequency conversion requires precise control over material properties and device architecture.
- Direct bonding offers a promising method for fabricating complex optical structures.
Purpose of the Study:
- To fabricate a periodically poled LiNbO3 planar waveguide buried in LiTaO3.
- To demonstrate efficient frequency doubling of a Nd:YAG laser using the fabricated waveguide.
- To characterize the performance of the device in terms of conversion efficiency and output beam quality.
Main Methods:
- Fabrication of a 12-mum -thick periodically poled LiNbO3 planar waveguide by direct bonding of precision-polished surfaces.
- Burial of the LiNbO3 waveguide within a LiTaO3 substrate.
- Frequency doubling of a 1064-nm continuous-wave (cw) diode-pumped Nd:YAG laser output.
- Operation at an elevated temperature of 174 degrees C with a 6.50-mum -period grating.
Main Results:
- Successful fabrication of the buried LiNbO3 planar waveguide.
- Demonstration of frequency doubling with a 5.5-mm-long device.
- Achieved a 4.3%W(-1) conversion efficiency for the second-harmonic generation.
- The generated green second-harmonic output exhibited fundamental-spatial-mode characteristics.
Conclusions:
- The direct bonding technique is effective for fabricating high-quality periodically poled LiNbO3 waveguides.
- The developed device demonstrates efficient nonlinear frequency conversion for laser applications.
- The fundamental-spatial-mode output is advantageous for various optical systems requiring high beam quality.
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