Photorefractive damage thresholds in Ti:LiNbO(3) channel waveguides

Area of Science:

• Optics and Photonics
• Materials Science
• Nonlinear Optics

Background:

• The photorefractive effect in lithium niobate (LiNbO3) is crucial for optical applications.
• Understanding its behavior in diffused waveguides is essential for device performance.
• Titanium diffusion is a common method for creating LiNbO3 waveguides.

Purpose of the Study:

• To experimentally and theoretically investigate the photorefractive effect in titanium-in-diffused LiNbO3 waveguides.
• To develop a predictive model for waveguide behavior under varying optical power.
• To differentiate the contributions of the photorefractive and thermal effects.

Main Methods:

• Experimental measurements of mode size and transmitted optical power versus input power.
• Theoretical modeling using diffusion constants and Kukhtarev's model parameters.
• Analysis of near-field intensity profiles at different optical intensities.
• Calculation of thermally induced index perturbation effects.

Main Results:

• Diffusion constants and Kukhtarev's model parameters were determined.
• A model was developed that accurately predicts waveguide behavior.
• Experimental and simulated results showed close agreement.
• Thermal effects were identified as secondary to the photorefractive effect.

Conclusions:

• The photorefractive effect in Ti:LiNbO3 waveguides can be accurately modeled.
• The developed model allows prediction of waveguide performance based on input power.
• Photorefractive nonlinearity is the dominant mechanism, with thermal effects being a minor perturbation.