16-microm infrared generation by difference-frequency mixing in diffusion-bonded-stacked GaAs

Area of Science:

• Nonlinear Optics
• Materials Science
• Quantum Electronics

Background:

• Gallium arsenide (GaAs) is a semiconductor with notable nonlinear optical properties.
• Efficient generation of tunable coherent radiation is crucial for various spectroscopic applications.
• Quasi-phase matching (QPM) techniques are essential for enhancing nonlinear optical processes.

Purpose of the Study:

• To generate tunable coherent radiation in the mid-infrared region.
• To demonstrate third-order quasi-phase matching in diffusion-bonded stacked GaAs.
• To assess the efficiency and phase-matching capabilities of the fabricated nonlinear optical device.

Main Methods:

• Utilized difference-frequency mixing in a 6-mm long, 24-layer diffusion-bonded stacked GaAs sample.
• Employed alternately rotated layers to achieve third-order quasi-phase matching.
• Measured the wavelength-tuning curve and conversion efficiency.

Main Results:

• Successfully generated tunable coherent radiation with wavelengths ranging from 15.6 to 17.6 micrometers.
• Achieved a maximum conversion efficiency of 0.7% (5% internal quantum efficiency) at 16.6 micrometers.
• Demonstrated that the diffusion-bonding process maintained nonlinear optical phase matching over the entire interaction length.

Conclusions:

• Diffusion-bonded stacked GaAs is a viable material for generating tunable mid-infrared coherent radiation.
• The third-order quasi-phase matching approach in this structure is effective for nonlinear optical frequency conversion.
• The experimental results align well with theoretical predictions, validating the fabrication and performance.