Phase-matching condition for THz wave generation via difference frequency generation using In_xGa_1-xSe mixed crystals.

Area of Science:

• Solid-state physics
• Optoelectronics
• Materials science

Background:

• Terahertz (THz) wave generation is crucial for various spectroscopic and imaging applications.
• Indium Gallium Selenide (InGaSe) is a promising nonlinear optical material for frequency conversion.
• Controlling the indium composition in InGaSe can tune its optical properties.

Purpose of the Study:

• To investigate the generation of Terahertz (THz) waves using InGaSe mixed crystals with varying indium compositions.
• To determine the effect of indium content on the phase-matching conditions for THz wave generation.

Main Methods:

• High-quality In_xGa_1-xSe mixed crystals with high indium compositions (x = 0.040, 0.048, 0.074) were grown from an indium flux.
• Terahertz (THz) waves were generated via difference frequency generation (DFG) at specific frequencies (9.7, 10.1, and 10.6 THz).
• The phase-matching angle for THz wave generation was experimentally measured for each indium composition.

Main Results:

• Terahertz (THz) waves were successfully generated in In_xGa_1-xSe crystals.
• The phase-matching angle required for THz wave generation was found to be dependent on the indium content.
• An increase in indium composition led to a shift in the phase-matching angle towards higher angles.

Conclusions:

• The indium content in In_xGa_1-xSe crystals significantly influences the phase-matching condition for Terahertz (THz) wave generation.
• These findings provide valuable insights for optimizing InGaSe crystals for efficient THz wave generation.
• The study demonstrates the potential of tailored InGaSe for tunable THz applications.