Modelling spontaneous four-wave mixing in periodically tapered waveguides

Area of Science:

• Nonlinear optics
• Quantum optics
• Materials science

Background:

• Quasi-phase-matching (QPM) schemes are crucial for efficient parametric interactions in nonlinear materials.
• Periodically tapered waveguides offer a novel approach to achieve QPM, particularly in third-order nonlinear systems.
• Spontaneous photon-pair emission is a key process for quantum information applications.

Purpose of the Study:

• To investigate the enhancement of spontaneous photon-pair emission using periodically tapered waveguides.
• To explore this technique in microstructured fibers and planar waveguides with sinusoidal cross-sections.
• To develop a quantum model for analyzing continuous and pulsed-pump excitations in such structures.

Main Methods:

• Development of a general, robust quantum model incorporating self- and cross-phase modulations.
• Simulation of photon-pair generation under continuous and pulsed-pump excitation.
• Analysis of waveguides with sinusoidally varying cross-sections.

Main Results:

• Significant enhancement in photon-pair generation was observed.
• The enhancement is particularly notable in waveguides with a small number of tapering periods.
• The proposed method is compatible with current fabrication technologies.

Conclusions:

• Periodically tapered waveguides are a promising technique for enhancing on-demand parametric interactions.
• The developed quantum model provides a valuable tool for studying these nonlinear processes.
• Further optimization of tapering patterns can tailor spectral properties of generated photons for quantum applications.