Laser irradiation precipitation from nonlinear optical KH₂PO₄ crystal

Area of Science:

• Materials Science
• Optics
• Crystallography

Background:

• The structural stability of Potassium Dihydrogen Phosphate (KDP) crystals is critical for nonlinear optical devices.
• Laser irradiation poses a significant challenge to the long-term integrity and performance of KDP-based technologies.

Purpose of the Study:

• To investigate the influence of laser wavelength on the structural stability of KDP crystals.
• To understand how different laser wavelengths induce changes in KDP crystal morphology and structure.

Main Methods:

• KDP crystals were irradiated using lasers at specific wavelengths (0.103 nm, 355 nm, and 785 nm).
• Precipitations formed on the KDP surface were analyzed for their morphology and crystalline phase using electron diffraction.
• Structural changes, particularly the periodicity of (001) planes, were examined.

Main Results:

• Laser irradiation at different wavelengths generated KDP precipitations with varying morphologies (irregular fusion, elongated prism, quasi-equiaxial).
• Electron diffraction confirmed all precipitations maintained the parent KDP phase.
• A noticeable irregularity in the stacked periodicity at the (001) planes of the precipitations was observed.

Conclusions:

• The wavelength of laser irradiation directly impacts the structural stability and precipitation characteristics of KDP crystals.
• Understanding these wavelength-dependent effects is crucial for enhancing the stability of KDP devices.
• Findings offer new insights for the design and construction of more robust KDP-based nonlinear optical systems.