Highly efficient four wave mixing in GaInP photonic crystal waveguides

Area of Science:

• Optoelectronics
• Nonlinear Optics
• Materials Science

Background:

• Ultrafast Kerr nonlinearity is crucial for optical signal processing.
• Two-photon absorption (TPA) and carrier effects can limit nonlinear performance in some materials.
• Photonic crystal waveguides offer enhanced light-matter interaction.

Purpose of the Study:

• To demonstrate and characterize highly efficient four-wave mixing (FWM) in GaInP photonic crystal waveguides.
• To investigate the impact of material properties on FWM efficiency at telecom wavelengths.
• To extract the nonlinear parameter (gamma) and compare it with theoretical predictions.

Main Methods:

• Fabrication of GaInP photonic crystal waveguides.
• Experimental setup for continuous-wave (cw) and pulsed four-wave mixing.
• Measurement of FWM efficiency as a function of pump-probe detuning and pump power.
• Analytical modeling to extract the nonlinear parameter gamma.

Main Results:

• Achieved high FWM conversion efficiencies of -49 dB for cw and -36 dB for pulsed pumps.
• Observed efficient nonlinear performance due to GaInP's large bandgap, avoiding TPA limitations at 1550 nm.
• Extracted nonlinear parameter gamma, showing strong dependence on the slow-down factor, reaching up to 2900 W⁻¹m⁻¹.
• Excellent agreement between experimental data and analytical model predictions.

Conclusions:

• GaInP photonic crystal waveguides are highly promising for efficient nonlinear optical applications at 1550 nm.
• The large bandgap of GaInP effectively mitigates TPA-related losses, enabling superior FWM performance.
• The demonstrated nonlinearities are consistent with theoretical expectations and self-phase modulation measurements.