Hybrid metasurface for ultra-broadband terahertz modulation

Heyes, Jane E.; Withayachumnankul, Withawat; Grady, Nathaniel K.; Chowdhury, Dibakar Roy; Azad, Abul K.; Chen, Hou-Tong

doi:10.1063/1.4901050

Cited by 42 publications

(33 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Heyes' s group (43) proposed a terahertz modulator composed of a planar array of metal cutwires on a SOS substrate, as shown in Fig.1. (b), where the silicon layer serves as photoconductive switches.…”

Section: Silicon (Si)mentioning

confidence: 99%

Review About the Optical-Controlled Terahertz Waves Modulator

Bai

Chen

et al. 2015

Applied Spectroscopy Reviews

View full text Add to dashboard Cite

A review of optical-controlled modulators in terahertz regime is presented. The regular semiconductor materials and organic materials at the terahertz frequencies enable fascinating modulation behaviors, including frequency shift, phase and amplitude modulation, observed in device of subwavelength dimensions.Modulation enhancement was realized by changing carrier concentration of local or whole surface in arrays of various structure cells involved with split-ring resonators, holes and apertures. We also illustrated some new methods to realize modulation for electromagnetic waves. Optical-controlled modulators and the novel manipulation methods will find amazing applications in terahertz communication, imaging and sensing.

show abstract

Section: Silicon (Si)mentioning

confidence: 99%

Review About the Optical-Controlled Terahertz Waves Modulator

Bai

Chen

et al. 2015

Applied Spectroscopy Reviews

View full text Add to dashboard Cite

show abstract

Section: Dielectric Materials As Spacers and Substrates At Terahertz mentioning

confidence: 99%

“…Dielectric materials of desired relative permittivity values have been employed as spacers in single and multilayer devices . These devices have either been demonstrated as freestanding devices or devices supported on a ground plane . With a suitable dielectric material and shape of the resonating element, a wide range of applications can be demonstrated based on the manipulation of polarization, phase, and amplitude of an incident electric field.…”

Section: Dielectric Materials As Spacers and Substrates At Terahertz mentioning

confidence: 99%

Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques

Ako

Upadhyay

Withayachumnankul

et al. 2019

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

on distinctive spectral signatures resulting from vibrational modes of covalent and hydrogen bonds. [8,[13][14][15][16] The focus on this spectrally rich region is attributed to the highly coherent and nonionizing nature of terahertz radiation, wide unallocated frequency bands, distinctive wavelengths, and their penetration through a significant depth of dielectric materials. Terahertz technology is geared toward realizing devices that can efficiently manipulate the phase, amplitude, and polarization of terahertz radiations for the above-mentioned myriad of applications.However, progress in this domain is held back by low terahertz power available from compact sources, high free-space path loss, and limited choice of materials that exhibit less absorption of terahertz waves. [17] Owing to the fact that natural materials demonstrate weak wave-matter interaction at terahertz frequencies, terahertz devices with engineered subwavelength resonant metallic inclusions on dielectric spacers have been realized, to interact strongly with an incident electromagnetic wave.In the past, metamaterials have been a promising route to building terahertz devices. These devices have in essence been engineered as 3D resonating elements that effectively manipulate both permittivity and permeability of an effective medium to couple to free space. The underlining disadvantage of these structures is the difficulty involved in the fabrication of 3D geometrical structures using standard semiconductor fabrication techniques. Standard fabrication techniques are generally amenable to 2D design with extrusion of these structures into thickness (the third, vertical dimension). Moreover, the choice and availability of dielectric materials and metals that provide sufficient interaction while retaining device efficiency has proved challenging. [13,[18][19][20] Recently, effective manipulation of electromagnetic wave has been widely demonstrated with 2D metasurfaces, which were originally employed as building blocks for 3D metamaterials. In these lower-dimension designs, effective manipulation of terahertz waves for various applications is achieved by carefully designing sub-wavelength resonant structures as is evident in published review articles. [21,22] Metasurfaces present high degree of compactness that enhances radiation efficiency. Additionally, the planar form factor of metasurfaces enables Manipulation of terahertz radiation opens new opportunities that underpin application areas in communication, security, material sensing, and characterization. Metasurfaces employed for terahertz manipulation of phase, amplitude, or polarization of terahertz waves have limitations in radiation efficiency which is attributed to losses in the materials constituting the devices. Metallic resonators-based terahertz devices suffer from high ohmic losses, while dielectric substrates and spacers with high relative permittivity and loss tangent also reduce bandwidth and efficiency. To overcome these issues, a proper choice of low loss and low relative permittivi...

show abstract

“…However, these methods normally result in the narrowband operations and bulky configurations. Recently developed metamaterials and metasurfaces 17,18 which exhibit exotic EM properties not found in nature, have attracted significant interest in the development of polarization converters, [19][20][21][22][23][24] resulting in numerous reflective and transmissive polarization converters with much reduced thicknesses. The recent developments aim at the realization of both the wide polarization conversion bandwidth and the high polarization conversion ratio (PCR), such as the microwave reflective metasurfaces, [2][3][4] gold helix structures in optics, 17 the planar ultrathin plasmonic metasurfaces at THz frequency, 11,[19][20][21][22] and other approaches.…”

Section: Introductionmentioning

confidence: 99%

“…Recently developed metamaterials and metasurfaces 17,18 which exhibit exotic EM properties not found in nature, have attracted significant interest in the development of polarization converters, [19][20][21][22][23][24] resulting in numerous reflective and transmissive polarization converters with much reduced thicknesses. The recent developments aim at the realization of both the wide polarization conversion bandwidth and the high polarization conversion ratio (PCR), such as the microwave reflective metasurfaces, [2][3][4] gold helix structures in optics, 17 the planar ultrathin plasmonic metasurfaces at THz frequency, 11,[19][20][21][22] and other approaches. [8][9][10][11][12][13][14][23][24][25][26][27][28][29] In addition, anisotropic frequency-selective surfaces (FSSs) 30,31 have been applied to convert linear polarization into circular polarization (LP-CP) in the microwave regime.…”

Section: Introductionmentioning

confidence: 99%

High‐efficiency cross and linear‐to‐circular polarization converters based on novel frequency selective surfaces

Wang

Lin

et al. 2019

Micro & Optical Tech Letters

View full text Add to dashboard Cite

Most high‐efficiency polarization converters in literatures are based on reflective structures. Here we report the designs and experiments of high‐efficiency transmissive polarization converters using novel compact frequency‐selective surfaces (FSSs). By combining the common dipole and square ring based band‐pass FSSs, a novel FSS can be generated, whose high‐efficiency pass bands and transmissive phases for two orthogonal polarizations can be tuned by changing the dimensions of the FSS structure. As demonstrations of the concept, a transmissive cross polarization converter (a half‐wave plate) and a transmissive linear‐to‐circular polarization (LP‐CP) converter (a quarter‐wave plate) are designed and tested, respectively. Simulated results show that the polarization conversion ratio over 90% for the transmissive cross‐polarization converter is from 18.5 to 23.5 GHz, about 23.8%, and the 3‐dB LP‐CP conversion bandwidth is 19.6%. Experiments are carried out to validate both designs.

show abstract

Hybrid metasurface for ultra-broadband terahertz modulation

Cited by 42 publications

References 33 publications

Review About the Optical-Controlled Terahertz Waves Modulator

Review About the Optical-Controlled Terahertz Waves Modulator

Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques

High‐efficiency cross and linear‐to‐circular polarization converters based on novel frequency selective surfaces

Contact Info

Product

Resources

About