Conical second harmonic generation in KDP crystal assisted by optical elastic scattering

Area of Science:

• Nonlinear Optics
• Solid State Physics
• Crystal Optics

Background:

• Second Harmonic Generation (SHG) is a key nonlinear optical process.
• Anomalous dispersion conditions can significantly alter SHG behavior.
• Phase-matching is crucial for efficient SHG in nonlinear crystals.

Purpose of the Study:

• To investigate the generation of phase-matching conical SHG in KDP crystals under anomalous dispersion.
• To understand the role of fundamental wave (FW) and scattering waves in achieving complete phase-matching.
• To analyze the implications of the observed SHG patterns for crystal symmetry and nonlinear coefficients.

Main Methods:

• Experimental observation of conical SHG in KDP crystals.
• Analysis of the double-ring pattern and intensity distribution of the SHG.
• Theoretical interpretation involving complete phase-matching assisted by FW and scattering waves.

Main Results:

• Observed phase-matching conical SHG under anomalous dispersion in KDP.
• The double-ring pattern indicates elastic scattering stimulating two polarization states.
• Inhomogeneous intensity of the SH ring relates to the effective nonlinear coefficient.

Conclusions:

• Complete phase-matching for conical SHG can be achieved with assistance from FW and scattering waves.
• The observed SHG patterns provide a method to investigate KDP crystal symmetry.
• The study highlights the influence of anomalous dispersion on nonlinear optical processes.