Suspended-core fiber with embedded GaSe nanosheets for second harmonic generation

Area of Science:

• Photonics and Nanomaterials Science
• Nonlinear Optics
• Fiber Optics

Background:

• Second Harmonic Generation (SHG) is crucial for frequency conversion.
• Integrating low-dimensional nonlinear materials into fiber platforms is challenging.
• Gallium Selenide (GaSe) nanosheets offer promising nonlinear optical properties.

Purpose of the Study:

• To demonstrate an all-fiber scheme for efficient SHG.
• To integrate GaSe nanosheets into a suspended-core fiber (SCF) for nonlinear applications.
• To explore the potential of SCFs as a platform for low-dimensional nonlinear materials.

Main Methods:

• Embedding GaSe nanosheets into a suspended-core fiber (SCF).
• Utilizing mode analysis and theoretical calculations to determine phase-matching conditions and optimal SCF length.
• Characterizing the SHG signal under milliwatt-level pump power and varying pump wavelengths.

Main Results:

• Achieved SHG signal with milliwatt-level pump light due to long-distance interaction.
• Observed quadratic growth of the SHG signal with pump power.
• Demonstrated SHG across a broad wavelength range (1420–1700 nm).

Conclusions:

• The proposed all-fiber scheme enables efficient SHG using GaSe nanosheets.
• Suspended-core fibers are an excellent platform for integrating low-dimensional nonlinear materials.
• This technology holds promise for applications in light sources, signal processing, and fiber sensing.