Topologically tuned terahertz confinement in a nonlinear photonic chip

Area of Science:

• Photonics and Metamaterials
• Condensed Matter Physics
• Electromagnetism

Background:

• Compact terahertz (THz) devices are crucial for high-speed communication and sensing.
• Challenges in THz technology include controlled generation, transport, and detection, particularly for chip-scale applications, due to coupling inefficiencies and absorption losses.

Purpose of the Study:

• To demonstrate nonlinear generation and topologically tuned confinement of THz waves.
• To explore the use of engineered lithium niobate chips with Su-Schrieffer-Heeger lattices for THz wave manipulation.
• To investigate the robustness of topological confinement against perturbations.

Main Methods:

• Utilized nonlinear generation of THz waves.
• Engineered a lithium niobate chip forming a wedge-shaped Su-Schrieffer-Heeger lattice.
• Experimentally measured band structures to visualize THz localization in momentum space.
• Analyzed the robustness of confined modes against chiral perturbations in trivial and nontrivial topological regimes.

Main Results:

• Successfully demonstrated topologically controlled confinement of THz waves.
• Provided direct visualization of THz localization in momentum space via measured band structures.
• Showcased the robustness of the confined THz mode against chiral perturbations.

Conclusions:

• Topological control of THz waves offers new possibilities for THz integrated circuits.
• This approach promises advancements in terahertz photonic applications.
• The engineered lithium niobate chip provides a platform for novel THz devices.