Presentation
4 October 2023 Nonlinear optical interactions in certain topological photonic systems
Author Affiliations +
Abstract
Topological photonics aims to utilize topological photonic bands and corresponding edge modes to implement robust light manipulation, which can be readily achieved in the linear regime of light-matter interaction. In this talk, I will review some recent results regarding nonlinear interactions of one-way edge-modes in frequency mixing processes in topological photonic crystals (PhCs) and graphene metasurfaces. In particular, I will demonstrate SHG via nonlinear interaction of double topological valley-Hall kink modes in PhCs with hexagonal lattice. I will first show that two topological frequency band gaps can be created around a pair of frequencies, ω0 and 2ω0, by gapping out the corresponding Dirac points. Importantly, I demonstrate that tunable, bidirectional phase-matched SHG via nonlinear interaction of the valley-Hall kink modes inside the two band gaps can be achieved. More specifically, by using Stokes parameters associated with the magnetic part of the valley-Hall kink modes, we introduce the concept of SHG directional dichroism, which is employed to characterize optical probes for sensing chiral molecules. I also show that these ideas can be extended to graphene metasurfaces, where the Kerr-type nonlinearity of graphene can be used to control the light transmission in topological domain-interface waveguides. In the second part of my talk I will illustrate how bound states in the continuum (BICs) of certain silicon nitride PhC slabs, engineered to possess sharp resonances with high quality factors at both the fundamental-frequency and second-harmonic, can be used to achieve an orders-of-magnitude enhancement of the SHG. Certain connections between the topological charge of the BICs and the properties of the nonlinear optical interaction (SHG) are also revealed.
Conference Presentation
© (2023) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Nicolae C. Panoiu, Jitong Wang, and Yupei Wang "Nonlinear optical interactions in certain topological photonic systems", Proc. SPIE PC12647, Active Photonic Platforms (APP) 2023, PC126471C (4 October 2023); https://doi.org/10.1117/12.2677161
Advertisement
Advertisement
KEYWORDS
Second harmonic generation

Photonics systems

Graphene

Molecules

Nonlinear transmission

Optical sensing

Optical transmission

Back to Top