High Q Resonant Sb2S3-Lithium Niobate Metasurface for Active Nanophotonics

Abstract

Phase change materials (PCMs) are attracting more and more attentions as enabling materials for tunable nanophotonics. They can be processed into functional photonic devices through customized laser writing, providing great flexibility for fabrication and reconfiguration. Lithium Niobate (LN) has excellent nonlinear and electro-optical properties, but is difficult to process, which limits its application in nanophotonic devices. In this paper, we combine the emerging low-loss phase change material Sb2S3 with LN and propose a new type of high Q resonant metasurface. Simulation results show that the Sb2S3-LN metasurface has extremely narrow linewidth of 0.096 nm and high quality (Q) factor of 15,964. With LN as the waveguide layer, strong nonlinear properties are observed in the hybrid metasurface, which can be employed for optical switches and isolators. By adding a pair of Au electrodes on both sides of the LN, we can realize dynamic electro-optical control of the resonant metasurface. The ultra-low loss of Sb2S3, and its combination with LN, makes it possible to realize a new family of high Q resonant metasurfaces for actively tunable nanophotonic devices with widespread applications including optical switching, light modulation, dynamic beam steering, optical phased array and so on.

Phase-change metasurfaces for dynamic image display and information encryption

“…As the phase transition to full crystallinity, the effective dielectric constant of chalcogenide PCM depends on the crystalline fraction m according to the Lorenz-Lorentz relation 49,52,68 , Based on the results on the dynamic nanoprinting and holographic image displays, it is confirmed that the phase-change metasurfaces offer an excellent platform to achieve the complete wavefront modulation across amplitude and phase spaces and dynamic multifunctionalities. In terms of information transmission, such a design provides the abundant degrees of freedom for a wide variety of applications associated with optical information encryption.…”

Roadmap for phase change materials in photonics and beyond

“…Figure 5 explains a chronological graph showing various PCM based platforms explored for tunable nanophotonic applications from UV to THz. This include PCMs such as gallium lanthanum sulfide GL, 47 Ge 2 Sb 2 Te 5 (GST) in near-IR (NIR), 48 , 49 , 50 , 51 , 52 GST in mid-IR (MIR) to THz, 22 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 GST in visible (VIS), 20 , 21 , 66 Ge 3 Sb 2 Te 6 in MIR, 67 , 68 Ge 3 Sb 2 Te 6 in NIR, 69 Ge 2 Sb 2 Se 4 Te 1 (GSST) in MIR, 70 GSST in NIR, 71 , 72 , 73 , 74 , 75 GST in VIS to NIR, 76 , 77 , 78 bismuth telluride (Bi:Te) in the VIS, 79 Sb 2 S 3 in the VIS to NIR, 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 Sb 2 Se 3 in the VIS to NIR. …”

“… 130 (C) Scheme of the resonant Sb 2 S 3 -LN metasurface with a pair of Au electrodes, with the reflection spectra showing the tunability and the shift of the plasmon resonance with different gate voltage from 0 V to 200 V. Adapted from. 84 …”

Nonvolatile Displays Based on Phase Change Materials

“…A recent study has focused on “customized” sub‐wavelength refractive index gratings consisting of periodic distributions of amorphous and crystalline PCMs, which can be “written,” “erased,” or “rewritten” by a tailored writing beam (laser or ion beam); [ 94 ] the geometric parameters (such as the structural period and duty cycle) can be modulated by controlling the excitation of the GMR [ 95 ] (Figure 7d). As the duty cycle decreases, the resonance wavelength is blue‐shifted, and the resonance peak, effective refractive index of the phase change layer, and absorption losses are reduced, resulting in a blue‐shift of the GMR and an increase in the Q‐factor.…”