Ultrabroadband midinfrared generation by using group-velocity-dispersion tailoring in a Bragg reflection waveguide...

Area of Science:

• Photonics
• Quantum Optics
• Materials Science

Background:

• Mid-infrared (mid-IR) light generation is crucial for various applications, including spectroscopy and sensing.
• Existing methods often face limitations in bandwidth and tunability.
• Gallium Nitride (GaN) based materials offer unique nonlinear optical properties for light generation.

Purpose of the Study:

• To propose and theoretically investigate a novel scheme for ultrabroadband mid-infrared generation.
• To leverage quasi-phase-matched difference-frequency generation (DFG) in a GaN/Al(x)Ga(1-x)N based Bragg reflection waveguide (BRW).
• To demonstrate broadband phase-matching through dispersion engineering.

Main Methods:

• Utilizing quasi-phase-matched difference-frequency generation (DFG).
• Designing symmetric Bragg reflection waveguides (BRWs) with tailored phase- and group-velocity dispersion.
• Simulating the maintenance of phase-matching conditions over a wide range of signal wavelengths.

Main Results:

• Achieved maintenance of the phase-matching condition over a broad range of signal wavelengths.
• Demonstrated the potential for generating a ~700 nm broad idler spectrum centered around 3.26 micrometers.
• Showcased the tunability of broadband features to desired spectral regions by adjusting photonic bandgap geometry.

Conclusions:

• The proposed BRW scheme offers a viable route for ultrabroadband mid-IR generation.
• Dispersion compensation using photonic bandgap geometry is effective for achieving broadband phase-matching.
• The concept is adaptable to different material systems and spectral regions within transparency limits.