Fabrication parameter optimization of a low-threshold high-efficiency proton-exchanged waveguide laser in Nd:LiTaO(3)

Area of Science:

• Materials Science
• Optics
• Solid-State Physics

Background:

• Proton-exchanged waveguides in lithium tantalate (LiTaO3) are crucial for integrated optics.
• Understanding the behavior of neodymium (Nd(3+)) ions in these waveguides is essential for laser applications.
• The phase diagram of H(x)Li(1-x)TaO3 influences material properties and device performance.

Purpose of the Study:

• To correlate Nd(3+) excited-state lifetime with the H(x)Li(1-x)TaO3 phase diagram.
• To optimize fabrication parameters for Nd:LiTaO3 waveguide lasers.
• To investigate the performance and stability of fabricated Nd:LiTaO3 waveguide lasers.

Main Methods:

• Proton exchange in lithium tantalate substrates.
• Characterization of Nd(3+) excited-state lifetime in waveguides.
• Fabrication of Nd:LiTaO3 waveguide lasers.
• Measurement of laser threshold and slope efficiency.
• Analysis of photorefractive effects.

Main Results:

• A clear correlation was established between Nd(3+) excited-state lifetime and the H(x)Li(1-x)TaO3 phase diagram.
• Optimized fabrication parameters led to a Nd:LiTaO3 waveguide laser with a low threshold of 2.9 mW.
• A high slope efficiency of 33% was achieved, matching predicted values.
• The fabricated laser component exhibited instabilities due to the photorefractive effect.

Conclusions:

• The study successfully linked material properties (phase diagram, excited-state lifetime) to waveguide laser performance.
• Optimized fabrication provides a pathway to efficient Nd:LiTaO3 waveguide lasers.
• Photorefractive effects remain a significant challenge for the stability of these devices.