Second harmonic generation in AlGaAs photonic wires using low power continuous wave light

Area of Science:

• Photonics
• Materials Science
• Quantum Optics

Background:

• Nonlinear optics enables frequency conversion in photonic devices.
• Aluminum gallium arsenide (AlGaAs) offers a high-index platform for integrated photonics.
• Efficient second harmonic generation (SHG) is crucial for telecommunications and quantum information processing.

Purpose of the Study:

• To achieve modal phase matched (MPM) second harmonic generation (SHG) in AlGaAs sub-micron ridge waveguides.
• To demonstrate efficient frequency conversion using low continuous wave (CW) powers.
• To explore the potential for integrated multi-functional photonic chips.

Main Methods:

• Fabrication of high-index contrast AlGaAs sub-micron ridge waveguides.
• Utilizing sub-wavelength design for phase matching and overlap efficiency.
• Experimental characterization of SHG conversion efficiency with sub-milliwatt CW powers.

Main Results:

• Achieved a normalized conversion efficiency of approximately 14%/W/cm².
• Demonstrated efficient SHG at telecommunication wavelengths.
• Confirmed the viability of AlGaAs waveguides for integrated nonlinear optics.

Conclusions:

• The developed AlGaAs waveguides enable efficient SHG with low optical powers.
• The device's properties facilitate integration into multi-functional photonic chips.
• Potential applications include wavelength division multiplexing and quantum entanglement generation.