Abstract-Optical control of terahertz plasmon-induced transparency based on hybrid CsPbBr3 quantum dot metasurfaces

Yue Yang, Jining Li, Jie Li, Jin Huang, Qingyan Li, Yating Zhang, Haitao Dai, and Jianquan Yao

(a) Schematic illustration of the CsPbBr3 QDs based PIT structure. (b) Optical microscopy of the designed metasurface. (c) Design dimensions of a unit cell. (d) PL intensity and absorption spectrum of CsPbBr3 QDs. The inset shows the TEM image of the synthesized QDs. (e) Measured transmission spectra of the PIT structure with and without spin-coating PEDOT: PSS/ CsPbBr3 QDs.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-28-16-24047

Incorporating photosensitive material into structured metamaterials explores opportunities for dynamical operation across the terahertz functional devices, enabled by the efficient interaction between light and matter. In this work, the CsPbBr3 quantum dots are incorporated into the metasurfaces, realizing the active control of the plasmon-induced transparency. In the experiment, the normalized modulation depth of transparency effect is up to 74%. Rigorous numerical and theoretical simulations verify that the variation of dynamic physical process is associated with the charge storage capacity in the capacitive metasurface. An observed phase advance and group delay indicate the hybrid metasurface is useful for slow light application. In addition, the simple process provides a convenient way for the development of terahertz functional devices.

© 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Demonstration of group delay above 40 ps at terahertz plasmon-induced transparency windows

Zhenyu Zhao, Hui Zhao, Rajour Tanyi Ako, Jianbing Zhang, Hongwei Zhao, and Sharath Sriram

. (a) Schematic diagram of a unit cell of proposed binary MM, in which p = 420 µm, r = 90 µm, w = 4 µm, h = 60 µm, g = 15 µm, respectively. l is the length of the metallic arc. (b) Microscopic images (VHX-500, Keyence Inc.) of unit cell of as-fabricated binary MM. (c) A schematic diagram showing terahertz transmission and group velocity delay through a periodic array of binary MM, as measured using a THz-TDS. KTHz refers to the wave vector of incident THz pulse. EX and HY refer to the electrical and magnetic component of the incident electromagnetic waves, respectively. XYZ are the coordinate axis in free space.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-19-26459

Herein, we demonstrate one of the highest terahertz group delay of 42.4 ps achieved experimentally at 0.23 THz, on a flexible planar metamaterial. The unit cell of metasurface is made up of a textured closed cavity and another experimentally concentric metallic arc. By tuning the central angle of the metallic arc, its intrinsic dipolar mode is in destructive interference with the spoof localized surface plasmon (SLSP) on textured closed cavity, which results in a plasmon-induced transparency phenomenon. The measured transmittances of as-fabricated samples using terahertz-time domain spectroscopy validate numerical results using extended coupled Lorentz oscillator model. It is found that the coupling coefficient and damping ratio of SLSP relies on the radius of the ring structure of textured closed cavity. As a consequence, the slow light maximum values become manoeuverable in strength at certain frequencies of induced transparency windows. To the best of our knowledge, our experimental result is currently the highest value demonstrated so far within metasurface at terahertz band.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Active control of terahertz plasmon-induced transparency in the hybrid metamaterial/monolayer MoS2/Si structure

Jie Ji,  Siyan Zhou,  Weijun Wang,  Furi Ling,  Jianquan Yao

https://pubs.rsc.org/en/Content/ArticleLanding/2019/NR/C8NR08813F#!divAbstract

Active control of terahertz wave is critical to the development of terahertz devices. Two dimensional materials with excellent optical properties provide more choices for opto-electrical devices with the maturity of their preparation technology. We proposed a hybrid structure of metamaterial/monolayer MoS2/Si and investigated its optical properties in terahertz range. The phenomenon of the plasmon-induced transparency (PIT) effect was observed in the transmission spectra, resulting from near-field coupling of two bright modes. According to simulated results, the phenomenon was confirmed its dependency on the length of the cutwire and distance between DSSRs. Furthermore, an external optical field supported by a 1064 nm laser could realized a switch effect on the sample. The resonances of the PIT metamaterial was disappeared when the optical power was further increased, as excited carriers in MoS2/Si substrate blocked the coupling effect. In addition, experimental results inferred that the PIT metamaterial enhanced the interaction of infrared light with monolayer MoS2/Si substrate.

Abstract-Liquid crystal terahertz modulator with plasmon-induced transparency metamaterial

Jing Wang, Hao Tian, Yu Wang, Xueyan Li, Yujie Cao, Li Li, Jianlong Liu, Zhongxiang Zhou

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-5-5769

An electrically tunable terahertz (THz) modulator with large modulation depth and low insertion loss is performed with liquid crystal (LC) metamaterial. The modulation depth beyond 90% and insertion loss below 0.5 dB are achievable at normal incidence by exploiting plasmon-induced transparency (PIT) effect. The PIT spectra can be manipulated by actively controlling the interference between dipole mode and nonlocal surface-Bloch mode with LC. The incident angle tuning effect on PIT spectra shows that the large modulation depth and low insertion loss can remain over a wide range of working angles. The superior property and simplicity of design make this modulator promising in advanced terahertz communication.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Tunable subwavelength terahertz plasmon-induced transparency in the InSb slot waveguide side-coupled with two stub resonators

Tunable subwavelength terahertz plasmon-induced transparency in the InSb slot waveguide side-coupled with two stub resonators Huaiqing Liu, Guobin Ren, Yixiao Gao, Yudong Lian, Yang Qi, and Shuisheng Jian  »View Author Affiliations

Applied Optics, Vol. 54, Issue 13, pp. 3918-3924 (2015)
http://dx.doi.org/10.1364/AO.54.003918

http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-54-13-3826

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We numerically investigated the realization of electromagnetically induced transparency (EIT) at the terahertz (THz) region in an InSb slot waveguide side-coupled with two stub resonators. The mechanism of the EIT phenomenon is theoretically analyzed and numerically studied by using coupled mode theory and the finite element method, respectively, and the theoretical results are in good agreement with the simulation results. The simulation results reveal that the EIT-like response is strongly dependent on the coupling separation between the two stub resonators, and we derived the best separation between the two stub resonators to get the most obvious EIT-like spectra. More importantly, the central wavelength of the EIT-like spectra can be actively controlled by tuning the temperature. This plasmonic waveguide system may have potential applications for ultracompact THz integrated circuits, such as thermo-tunable filters, THz switching, slow-light components, and THz sensitive sensors.

© 2015 Optical Society of America