Photorefractive-damage-resistant Zn-diffused waveguides in MgO:LiNbO(3).

Area of Science:

• Materials Science
• Optical Engineering
• Solid State Physics

Background:

• Lithium niobate (LiNbO3) is a key material for integrated optics.
• Magnesium oxide-doped lithium niobate (MgO:LiNbO3) offers enhanced photorefractive resistance.
• Optical waveguides are essential components for manipulating light in photonic devices.

Purpose of the Study:

• To fabricate planar optical waveguides using zinc diffusion in MgO:LiNbO3 and LiNbO3.
• To characterize the optical properties and propagation losses of the fabricated waveguides.
• To assess the photorefractive damage resistance of Zn-diffused waveguides in MgO:LiNbO3.

Main Methods:

• Planar waveguides were fabricated by diffusing zinc (Zn) into MgO:LiNbO3 and LiNbO3 substrates.
• Propagation losses were measured at a wavelength of 633 nm.
• Photorefractive damage was investigated using single-beam-induced in-plane scattering at 515 nm.

Main Results:

• Zn-diffused waveguides in MgO:LiNbO3 successfully guided both ordinary and extraordinary polarization.
• Propagation losses for these waveguides were measured to be between 0.4 and 1.2 dB/cm at 633 nm.
• No single-beam-induced in-plane scattering due to photorefractive damage was observed up to intensities of 90 kW/cm(2) at 515 nm.

Conclusions:

• Zinc diffusion is an effective method for creating low-loss, polarization-guiding waveguides in MgO:LiNbO3.
• MgO:LiNbO3 exhibits significant resistance to photorefractive damage, making it suitable for high-power optical applications.
• These findings support the use of Zn-diffused MgO:LiNbO3 waveguides in advanced photonic integrated circuits.