Extraordinary-mode refractive-index change produced by the linear electro-optic effect in LiNbO(3) and reverse-poled...

Area of Science:

• Photonics and Materials Science
• Integrated Optics
• Electro-optics

Background:

• Lithium niobate (LiNbO3) is a key material for integrated photonic devices.
• Understanding electro-optic effects is crucial for developing advanced sensors.
• Previous models may not fully capture index changes in poled LiNbO3.

Purpose of the Study:

• To calculate the electro-optically induced refractive index change in LiNbO3.
• To analyze the dependence of index change on electric field magnitude and direction.
• To provide a general formula for electro-optic index change in LiNbO3.

Main Methods:

• Numerical eigenvalue procedure to diagonalize the impermeability tensor.
• Vector reference-frame transformation and small perturbation approximation for index calculation.
• Tensor reference-frame transformation to determine electro-optic coefficients for reverse-poled LiNbO3.

Main Results:

• Quantified refractive index change in regular and reverse-poled LiNbO3.
• Established the relationship between index change and electric field parameters.
• Derived a general formula applicable to various electric field configurations.

Conclusions:

• The developed index-calculation procedure is versatile and applicable beyond this specific study.
• Accurate electro-optic characterization of LiNbO3 is essential for photonic electric-field sensor optimization.
• Findings contribute to the design of more sensitive and precise integrated photonic sensors.