1：Experimental Design and Method Selection:

The study investigates the formation of ordered defect structures in lithium niobate (LN) crystals under different non-equilibrium processes: photorefractive effect, laser ablation, and mechanical stress. Crystals of different chemical compositions (LiNbO3stoich, LiNbO3:Cu(

2：57):

Gd(

3：07 wt %), LiNbO

Mg (

4：69 wt %), LiNbO

Zn(2 wt % in a crystal),B(0.1 wt % in a melt)) were selected based on their specific properties (e.g., strong photorefractive effect, high electron conductivity). Methods include laser irradiation (continuous and pulsed), laser ablation, acid etching, and mechanical stress application, with analysis using optical microscopy, atomic force microscopy, and image processing.

5：1 wt % in a melt)) were selected based on their specific properties (e.g., strong photorefractive effect, high electron conductivity). Methods include laser irradiation (continuous and pulsed), laser ablation, acid etching, and mechanical stress application, with analysis using optical microscopy, atomic force microscopy, and image processing. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples were cut from Czochralski-grown boules into cuboids (7×6×5 mm3) with edges aligned to crystallographic axes X, Y, Z. Specific crystals were chosen: LiNbO3stoich (grown from melt with

6：6 mol.% Li2O), LiNbO

Cu(

7：57):

Gd(

8：07 wt %) and LiNbO

Mg (

9：69 wt %) (grown from congruent melt), and LiNbO

Zn(2 wt % in a crystal),B(0.1 wt % in a melt) (grown from congruent melt with 0.1 wt% boron). Data sources include digital images from cameras and microscopes, with raw and processed data available in referenced repositories.

10：1 wt % in a melt) (grown from congruent melt with 1 wt% boron). Data sources include digital images from cameras and microscopes, with raw and processed data available in referenced repositories. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment includes MLL-100 Y:Al-garnet laser (532 nm), UP-266 MACRO laser system (Nd:YAG laser, λ=266 nm), digital photo camera SONY NEX-F3, optical microscope Axio Observer.D1m (Carl Zeiss), atomic force microscope АСМ Nano-R2 (Pacific Nanotechnology), image analysis system 'Thixomet' with program 'Thixomet Standard', and software Gimp

11：7 and Microsoft Excel. Materials include lithium niobate crystals, acid mixture (HNO

HF = 3:1), argon gas (≥99.95% purity), and light-tight shield (black paper).

12：95% purity), and light-tight shield (black paper). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: For photorefractive effect in LiNbO3stoich, a 532 nm laser irradiated the crystal, with images captured after 60s using a camera; the laser spot was covered to avoid over-illumination. For laser ablation in LiNbO3:Cu(

13：57):

Gd(

14：07 wt %) and LiNbO

Mg (

15：69 wt %), pulsed laser (266 nm) ablation was performed in argon atmosphere with specific parameters (e.g., frequency 10 Hz, pulse duration 4 ns, energy densities 1 J/cm2 and 180 J/cm2). Surfaces were etched twice with acid mixture (first 18h, second 24h) to reveal defects. For mechanical stress in LiNbO

Zn(2 wt % in a crystal),B(0.1 wt % in a melt), cracks were induced and analyzed. Imaging was done in dark and light fields, and AFM scanning in 'constant force' mode. Defect counting and distance measurements were performed manually in Gimp and analyzed in Excel.

16：1 wt % in a melt), cracks were induced and analyzed. Imaging was done in dark and light fields, and AFM scanning in 'constant force' mode. Defect counting and distance measurements were performed manually in Gimp and analyzed in Excel. Data Analysis Methods:

5. Data Analysis Methods: Data analysis involved statistical counting of defects and domains in concentric areas using Gimp 2.7 and Microsoft Excel. Distances were measured in relative units, and dependencies (e.g., number of defects vs. distance) were plotted. Image processing included converting colored images to grayscale for contrast enhancement. Patterns in defect distribution were identified through summation in concentric zones of varying thicknesses.