2D Layered Graphene Oxide Films Integrated with Micro-Ring Resonators for Enhanced Nonlinear Optics

Area of Science:

• Photonics
• Materials Science
• Nonlinear Optics

Background:

• Micro-ring resonators (MRRs) are key components in integrated photonics.
• Graphene oxide (GO) exhibits promising nonlinear optical properties.
• Integrating 2D materials with photonic devices is an active research area.

Purpose of the Study:

• To demonstrate enhanced nonlinear optical performance by integrating graphene oxide (GO) films with micro-ring resonators (MRRs).
• To investigate the effect of GO film thickness and patterning on nonlinear optical efficiency.
• To explore the physical insights into GO's third-order nonlinearity.

Main Methods:

• Fabrication of complementary-metal-oxide-semiconductor (CMOS)-compatible doped silica MRRs.
• Large-area, transfer-free, layer-by-layer GO coating with precise thickness control.
• Photolithography and lift-off processes for patterned GO films.
• Four-wave-mixing (FWM) measurements under varying pump powers and resonant wavelengths.

Main Results:

• Significant enhancement in FWM efficiency: ≈7.6 dB for 1-layer uniform GO and ≈10.3 dB for 50-layer patterned GO.
• Experimental results show good agreement with theoretical predictions.
• Extracted third-order nonlinearity of GO, revealing layer-dependent behavior from 2D to quasi-bulk.

Conclusions:

• Integrated photonic resonators with 2D layered GO films exhibit high nonlinear optical performance.
• GO films offer a promising route for enhancing nonlinear optics in integrated photonic devices.
• The study provides valuable physical insights into the nonlinear optical properties of GO.