Abstract-Active thermal modulation of electromagnetically induced transparency at terahertz frequencies

 

Wentao Zhang, Hongyang Li, Shan Yin, Wei Huang, Xintong Shi, Yuting Zhang, 

https://www.spiedigitallibrary.org/journals/optical-engineering/volume-59/issue-12/127111/Active-thermal-modulation-of-electromagnetically-induced-transparency-at-terahertz-frequencies/10.1117/1.OE.59.12.127111.short?SSO=1

We present thermal control of electromagnetically induced transparency (EIT) by actively modulating the dark mode in terahertz (THz) metamaterials, including a cut wire and a split-ring resonator (SRR). By integrating indium antimonide (InSb) into the SRR and increasing the temperature, the active modulation of EIT is realized. The coupling mechanism is numerically analyzed through the coupled oscillator model, and the result of fitting the EIT intensity agrees well with the simulation results when the temperature changes from 200 to 240 K. By analyzing the electric field distribution, the physical mechanism is the change in the damping rate of the dark mode resonator due to the increase in InSb temperature. Our work has practical significance in designing tunable THz functional devices.

© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE) 0091-3286/2020/$28.00 © 2020 SPIE

Abstract-Adiabatic following of terahertz surface plasmon-polaritons based on tri-layered corrugated thin film coupler

Wei Huang, Shan Yin, Wentao Zhang, Kaili Wang, Yuting Zhang, Jiaguang Han

https://arxiv.org/abs/1901.08424

In this paper, we utilize coupled mode theory (CMT) to model the coupling of surface plasmon polaritons (SPPs) between tri-layered corrugated thin films (CTF) structure coupler in the terahertz region. Employing the stimulated raman adiabatic passage (STIRAP) quantum control technique, we propose a novel directional coupler based on SPPs evolution in tri-layered CTF in some curved configuration. Our calculated results show that the SPPs can be completely transferred from the input to the output CTF waveguides, and even we consider SPPs propagation loss, the transfer rate is still above 70%. The performance of our coupler is also robust that it is not sensitive to the geometry of device and wavelength of SPPs. As a result, our device can tolerate defect induced by fabrication and manipulate THz wave at broadband.

Abstract-Adiabatic control of surface plasmon-polaritons in a 3-layers graphene curved configuration

Wei Huang,  Shi-Jun Liang,  L.K. Ang,

http://www.sciencedirect.com/science/article/pii/S0008622317310886

In this paper, we utilize coupled mode theory (CMT) to model the coupling between surface plasmon-polaritons (SPPs) between multiple graphene sheets. By using the Stimulated Raman Adiabatic Passage (STIRAP) Quantum Control Technique, we propose a novel directional coupler based on SPPs evolution in three layers of graphene sheets in some curved configuration. Our calculated results show that the SPPs can be transferred efficiently from the input graphene sheet to the output graphene sheet, and the coupling is also robust that it is not sensitive to the length of the device configuration's parameters and excited SPPs wavelength.

Abstract-THz Wave Modulator Based on the Decay of THz Surface Plasmon along an Intrinsic InSb Surface

Tao Yang, Bing Jiang, Ho-pui Ho, Yong-yuan Zhu, Wei Huang

http://iopscience.iop.org/article/10.1088/1742-6596/844/1/012038

THz surface plasmon are decayed exponentially when propagating along the surface of a semiconductor. A metal razor blade is used to couple THz surface plasmon to THz waves at different position on the surface of an indium antimonide wafer. Thus the intensity of the output THz wave is modulated.

Abstract-Detection of defects on the surface of a semiconductor by terahertz surface plasmon polaritons

Tao Yang, Yuanyi Li, Rayko Stantchev, Yongyuan Zhu, Yiqiang Qin, Xinhui Zhou, and Wei Huang
https://www.osapublishing.org/ao/abstract.cfm?uri=ao-55-15-4139

We propose a new method for detecting small defects on the surface of a semiconductor by analyzing the transmission spectrum of terahertz surface plasmon polaritons. The field distributions caused by the detection of defects of different sizes are simulated. Experimentally, using a terahertz time domain spectrometer, we measure the transmission spectrum of terahertz surface plasmon polaritons passing through particles on the surface of an intrinsic InSb wafer. Our results show that the measured temporal waveform and frequency spectra are distinctly changed due to the presence of the particles, thereby confirming the effectiveness of this method for detecting defects. For increased detection efficiency, the frequency of the surface plasmon polaritons has to be slightly lower than the plasma frequency of the semiconductor. In comparison with traditional methods, our approach offers the merits of detecting both on-surface and subsurface defects, which is critical in monitoring the quality of semiconductor wafers.

© 2016 Optical Society of America

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