Electric-field-induced optical path length change in LiNbO3:MgO crystals: spatial anisotropy analysis

Area of Science:

• Materials Science
• Optoelectronics
• Solid State Physics

Background:

• Anisotropic crystals exhibit complex responses to electric fields, crucial for optoelectronic devices.
• Piezoelectric deformation significantly influences optical properties under electric fields.
• Understanding electric-field-induced optical path length change (EFIOPC) is key for device optimization.

Purpose of the Study:

• To develop a methodology for calculating EFIOPC in anisotropic crystals, incorporating piezoelectric deformation.
• To analyze the impact of inverse piezoelectricity on EFIOPC.
• To identify optimal crystal orientations for enhanced electro-optic performance.

Main Methods:

• Calculation of indicative surfaces (ISs) for EFIOPC.
• Detailed analysis for crystals with 3m point group symmetry.
• Application to lithium niobate single crystals doped with magnesium oxide (LiNbO(3):MgO).

Main Results:

• Inverse piezoelectricity considerably modifies EFIOPC, affecting extreme directions and directional maxima.
• Indicative surfaces of EFIOPC are crucial for determining optimal electro-optic coupling geometries.
• LiNbO(3):MgO crystals with an X/50° cut offer the lowest effective driving voltage.

Conclusions:

• The inclusion of piezoelectric deformation is essential for accurate EFIOPC calculations in anisotropic materials.
• Optimized crystal cuts, such as X/50° in LiNbO(3):MgO, enhance electro-optic cell performance.
• The proposed methodology and findings provide a pathway for designing more efficient electro-optic devices.