Effect of electro-optic modulation on coupled quasi-phase-matched frequency conversion.

Area of Science:

• Nonlinear optics
• Materials science
• Condensed matter physics

Background:

• The electro-optic effect allows modulation of a material's refractive index with an applied electric field.
• Optical superlattices exhibit unique light-matter interaction properties due to their periodic structure.
• Quasi-phase matched processes are crucial for efficient nonlinear frequency conversion.

Purpose of the Study:

• To investigate the use of the electro-optic effect for controlling nonlinear frequency conversion in optical superlattices.
• To explore the generation of third harmonic light through modulation of refractive index.
• To demonstrate a method for efficient and tunable third harmonic generation.

Main Methods:

• Numerical simulations were performed on periodic and quasi-periodic optical superlattices.
• The electro-optic effect was employed to modulate the refractive index, inducing quasi-phase mismatches.
• Coupled quasi-phase matched processes were analyzed to observe energy redistribution.

Main Results:

• Modulating the refractive index with an external DC electric field effectively controlled quasi-phase mismatches.
• Energy redistribution among optical waves was observed due to induced quasi-phase mismatches.
• Efficient third harmonic generation was numerically achieved by varying the external electric field.

Conclusions:

• The electro-optic effect offers a viable method for controlling nonlinear frequency conversion in optical superlattices.
• External electric field modulation provides a simple and convenient way to tune third harmonic generation efficiency.
• This approach enables precise control over energy transfer in coupled quasi-phase matched processes.