MEMS reconfigurable metamaterial for terahertz switchable filter and modulator

Han, Zhonghua; Kohno, Kenta; Fujita, Hiroyuki; Hirakawa, Kazuhiko; Toshiyoshi, Hiroshi

doi:10.1364/oe.22.021326

Cited by 134 publications

(86 citation statements)

References 27 publications

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“…Alternatively, a vertically aligned capacitor is reported in Ref. [60] with an air gap which can be electrically tuned between two thicknesses with resonance frequencies at 0.45 and 0.7 THz, as shown in Figure 5A and B. The modulation mechanism is very effective and reaches 16.5 dB modulation depth, as shown by the dots in Figure 5C.…”

Section: Microelectromechanical Systemsmentioning

confidence: 98%

“…As these resonances are fundamentally based on the structural dimensions of the metamaterial pattern, physically changing the shape of the resonant components in these arrays has a strong effect on the resonance conditions. MEMS have been used to physically alter the resonant components of individual unit cells in metamaterials, leading to the realization of active, electronically tunable THz devices [58][59][60][61][62]. MEMS are advantageous, as unit cells can be individually addressed electronically, increasing the range of tuning parameters.…”

Section: Microelectromechanical Systemsmentioning

confidence: 99%

“…Similar THz device designs are demonstrated in Refs. [59,60] for the active control of the metamaterial frequency response. Both of these approaches employ a SRR metamaterial geometry with a movable capacitance arm on the application of a bias.…”

Section: Microelectromechanical Systemsmentioning

confidence: 99%

“…MEMS tuning is a very flexible way of building THz devices, as there are a myriad of possible design architectures to be employed. The LC resonance of SRRs is critically dependent on the capacitive gap, which has been taken advantage of to demonstrate large frequency shifts [59,60]. There is, however, a fabrication limit to how small the geometry of such devices can be to operate efficiently, and most devices are observed to work under 1 THz as the surface area-to-volume ratio becomes unfavourable at higher frequencies.…”

Section: Microelectromechanical Systemsmentioning

confidence: 99%

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All-integrated terahertz modulators

et al. 2017

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Terahertz (0.1-10 THz corresponding to vacuum wavelengths between 30 μm and 3 mm) research has experienced impressive progress in the last few decades. The importance of this frequency range stems from unique applications in several fields, including spectroscopy, communications, and imaging. THz emitters have experienced great development recently with the advent of the quantum cascade laser, the improvement in the frequency range covered by electronic-based sources, and the increased performance and versatility of time domain spectroscopic systems based on full-spectrum lasers. However, the lack of suitable active optoelectronic devices has hindered the ability of THz technologies to fulfill their potential. The high demand for fast, efficient integrated optical components, such as amplitude, frequency, and polarization modulators, is driving one of the most challenging research areas in photonics. This is partly due to the inherent difficulties in using conventional integrated modulation techniques. This article aims to provide an overview of the different approaches and techniques recently employed in order to overcome this bottleneck.

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Section: Microelectromechanical Systemsmentioning

confidence: 98%

Section: Microelectromechanical Systemsmentioning

confidence: 99%

Section: Microelectromechanical Systemsmentioning

confidence: 99%

Section: Microelectromechanical Systemsmentioning

confidence: 99%

See 2 more Smart Citations

All-integrated terahertz modulators

et al. 2017

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“…The versatility of MEMS design has enabled active manipulation of numerous THz properties such as magnetic resonance, [19][20][21][22] electrical resonance, [23][24][25] anisotropy, [ 26 ] broadband response, [ 27 ] isotropic resonance switching [ 28 ] multiresonance switching, [29][30][31] and coupling strength between resonators. [ 32 ] The enhanced controllability and direct integration of MEMS actuators into metamaterial unit cell geometry is an ideal fi t for the realization of selective control of coupled mode resonators.…”

Section: Communicationmentioning

confidence: 99%

Active Control of Electromagnetically Induced Transparency Analog in Terahertz MEMS Metamaterial

Pitchappa

Manjappa

et al. 2016

Advanced Optical Materials

213

120

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541wileyonlinelibrary.com COMMUNICATIONand their possible applications. The ultimate form of active manipulation of EIT phenomenon will be when all three primary parameters are controlled independently. The independent control of individual resonators demands for the controllability at unit cell level, and conventional approaches such as optical pumping of photoconductive elements or thermally controlled superconductor are restricted to provide only global control.Recently, microelectromechanical systems (MEMS) based tunable metamaterials have been reported to achieve controllability at unit cell level, along with the added advantage of being electrically controlled, miniaturized size and enhanced electrooptic performance. The versatility of MEMS design has enabled active manipulation of numerous THz properties such as magnetic resonance, [19][20][21][22] electrical resonance, [23][24][25] anisotropy, [ 26 ] broadband response, [ 27 ] isotropic resonance switching [ 28 ] multiresonance switching, [29][30][31] and coupling strength between resonators. [ 32 ] The enhanced controllability and direct integration of MEMS actuators into metamaterial unit cell geometry is an ideal fi t for the realization of selective control of coupled mode resonators. In this Communication, reconfi gurable metamaterial with independently controlled bright and dark mode resonators is proposed for advanced manipulation of the classical analog of EIT and slow light effects in THz spectral region. The active control of bright mode resonator enables modulation of EIT intensity, while the tuning of dark mode resonance causes the EIT peak to tune in frequency. Furthermore, simultaneous switching of bright and dark mode resonators results in dynamic switching of the system between coupled and uncoupled states. The proposed approach of selective reconfi guration can be scaled for multiresonator systems, which can be coupled either through inductive, capacitive, or conductive means.The metamaterial consists of 80 × 80 periodic array of cut wire resonator (CWR) with closely placed split ring resonators (SRRs), as shown in Figure 1 and Figure 2 . The periodicity of unit cell is 100 µm along both axial directions. The CWR has length, l C = 60 µm and width, w C = 5 µm, respectively. The SRRs have a base length, b S = 30 µm, side length, l S = 20 µm, and split gap, g S = 4 µm. The SRRs are placed at a distance of S = 2 µm from the CWR. When the polarization of the excitation fi eld is along the CWR arm, the dipole mode resonance of the CWR will be the bright mode and the inductive-capacitive (LC) mode of SRR resonance acts as the dark mode. Thus for the incident THz polarization, the direct excitation of the bright mode induces image charges on the nearby SRRs through nearfi eld inductive coupling, thereby exciting the LC resonance of the SRRs. These bright-dark resonances have contrasting line widths with identical resonance frequencies and under a strong coupling regime they experience an EIT-type of interference that gives rise to a sharp transm...

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