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Jung H, Hale LL, Gennaro SD, Briscoe J, Iyer PP, Doiron CF, Harris CT, Luk TS, Addamane SJ, Reno JL, Brener I, Mitrofanov O. Terahertz Pulse Generation with Binary Phase Control in Nonlinear InAs Metasurface. NANO LETTERS 2022; 22:9077-9083. [PMID: 36367359 DOI: 10.1021/acs.nanolett.2c03456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The effect of terahertz (THz) pulse generation has revolutionized broadband coherent spectroscopy and imaging at THz frequencies. However, THz pulses typically lack spatial structure, whereas structured beams are becoming essential for advanced spectroscopy applications. Nonlinear optical metasurfaces with nanoscale THz emitters can provide a solution by defining the beam structure at the generation stage. We develop a nonlinear InAs metasurface consisting of nanoscale optical resonators for simultaneous generation and structuring of THz beams. We find that THz pulse generation in the resonators is governed by optical rectification. It is more efficient than in ZnTe crystals, and it allows us to control the pulse polarity and amplitude, offering a platform for realizing binary-phase THz metasurfaces. To illustrate this capability, we demonstrate an InAs metalens, which simultaneously generates and focuses THz pulses. The control of spatiotemporal structure using nanoscale emitters opens doors for THz beam engineering and advanced spectroscopy and imaging applications.
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Affiliation(s)
- Hyunseung Jung
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Lucy L Hale
- Electronic and Electrical Engineering, University College London, London WC1E 7JE, U.K
| | - Sylvain D Gennaro
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Jayson Briscoe
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Prasad P Iyer
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Chloe F Doiron
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - C Thomas Harris
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Ting Shan Luk
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Sadhvikas J Addamane
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - John L Reno
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Igal Brener
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
| | - Oleg Mitrofanov
- Sandia National Laboratories, Albuquerque, New Mexico 87123, United States
- Electronic and Electrical Engineering, University College London, London WC1E 7JE, U.K
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Broadband Terahertz Photonic Integrated Circuit with Integrated Active Photonic Devices. PHOTONICS 2021. [DOI: 10.3390/photonics8110492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Present-day photonic terahertz (100 GHz–10 THz) systems offer dynamic ranges beyond 100 dB and frequency coverage beyond 4 THz. They yet predominantly employ free-space Terahertz propagation, lacking integration depth and miniaturisation capabilities without sacrificing their extreme frequency coverage. In this work, we present a high resistivity silicon-on-insulator-based multimodal waveguide topology including active components (e.g., THz receivers) as well as passive components (couplers/splitters, bends, resonators) investigated over a frequency range of 0.5–1.6 THz. The waveguides have a single mode bandwidth between 0.5–0.75 THz; however, above 1 THz, these waveguides can be operated in the overmoded regime offering lower loss than commonly implemented hollow metal waveguides, operated in the fundamental mode. Supported by quartz and polyethylene substrates, the platform for Terahertz photonic integrated circuits (Tera-PICs) is mechanically stable and easily integrable. Additionally, we demonstrate several key components for Tera-PICs: low loss bends with radii ∼2 mm, a Vivaldi antenna-based efficient near-field coupling to active devices, a 3-dB splitter and a filter based on a whispering gallery mode resonator.
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Liu D, Zhao S, You B, Jhuo SS, Lu JY, Chou S, Hattori T. Tuning transmission properties of 3D printed metal rod arrays by breaking the structural symmetry. OPTICS EXPRESS 2021; 29:538-551. [PMID: 33726287 DOI: 10.1364/oe.397474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
In this work, one metallic photonic crystal waveguide composed of periodic metal rod arrays (MRAs) is experimentally and numerically demonstrated in terahertz frequencies. Such waveguides fabricated by 3D printers exhibit two resonant modes: the fundamental mode and the high-order mode, separating by a broad bandgap. Compared to the fundamental mode, the high-order mode shows higher field confinement and more sensitive to the geometry changes. By breaking the structure parameter, i.e., increasing or decreasing the metal rod interspace, the spectral positions, bandwidths, as well as the transmittances of high-order modes can be optimized. With broken symmetry in MRAs, the third resonant mode having high transmittance has emerged in the transmission spectrum. Results showing that fine-tuning in the alignment of metal rods leads to a great change in the transmission of high-order modes. These findings suggest that the transportation efficiency of THz waves through an MRA is tunable by breaking the structural symmetry.
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Siday T, Natrella M, Wu J, Liu H, Mitrofanov O. Resonant terahertz probes for near-field scattering microscopy. OPTICS EXPRESS 2017; 25:27874-27885. [PMID: 29092256 DOI: 10.1364/oe.25.027874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/10/2017] [Indexed: 06/07/2023]
Abstract
We propose and characterize a scattering probe for terahertz (THz) near-field microscopy, fabricated from indium, where the scattering efficiency is enhanced by the dipolar resonance supported by the indium probe. The scattering properties of the probe were evaluated experimentally using THz time-domain spectroscopy (TDS), and numerically using the finite-difference time-domain (FDTD) method in order to identify resonant enhancement. Numerical measurements show that the indium probes exhibit enhanced scattering across the THz frequency range due to dipolar resonance, with a fractional bandwidth of 0.65 at 1.24 THz. We experimentally observe the resonant enhancement of the scattered field with a peak at 0.3 THz. To enable practical THz microscopy applications of these resonant probes, we also demonstrate a simple excitation scheme utilizing a THz source with radial polarization, which excites a radial mode along the length of the tip. Strong field confinement at the apex of the tip, as required for THz near-field microscopy, was observed experimentally.
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