Efficient green-light generation by proton-exchanged periodically poled MgO:LiNbO3 ridge waveguide.

Area of Science:

• Nonlinear optics
• Materials science
• Integrated photonics

Background:

• Efficient generation of green light is crucial for various applications.
• Periodically poled lithium niobate (PPLN) waveguides are commonly used for nonlinear frequency conversion.
• Optimizing waveguide fabrication is key to enhancing device performance.

Purpose of the Study:

• To demonstrate efficient continuous-wave (cw) 532 nm green-light generation.
• To investigate the performance of MgO:LiNbO3 ridge waveguides with varying widths.
• To optimize the fabrication process for high conversion efficiency.

Main Methods:

• Fabrication of periodically poled MgO:LiNbO3 ridge waveguides using annealed proton exchange and precise dicing.
• Characterization of waveguide performance with different widths.
• Measurement of green output power and conversion efficiency under coupled fundamental light power.

Main Results:

• A 6-μm-wide, 1.6-cm-long uncoated ridge waveguide achieved 127 mW of green output power.
• The device operated under 250 mW of coupled fundamental light power.
• The highest achieved conversion efficiency reached 53%.

Conclusions:

• The combined annealed proton exchange and dicing process is effective for fabricating high-performance MgO:LiNbO3 ridge waveguides.
• Optimized waveguide dimensions are critical for efficient green-light generation.
• This work presents a promising approach for compact and efficient green light sources.