A Polarization-Resolved Study of Nanopatterned Photoconductive Antenna for Enhanced Terahertz Emission

Rana, Goutam; Bhattacharya, Arkabrata; Gupta, Abhishek; Ghindani, Dipa; Jain, Ravikumar; Duttagupta, Siddhartha P.; Prabhu, S. S.

doi:10.1109/tthz.2019.2891022

Cited by 19 publications

(9 citation statements)

References 43 publications

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“…It can be clearly seen that although different PCAs do have amplitude fluctuation, the range of the error is not sufficient to affect the conclusion: the band‐stop and band‐pass resonances at 0.34 and 0.54 THz are definitely present. Comparing with previous nanostructure‐assisted PCA which focuses on enhancing the overall THz power, [ 11–21 ] the proposed micron‐scale SRRs here achieve the manipulation of the spectral characteristics of PCA which is rarely been realized and discussed.…”

Section: Resultsmentioning

confidence: 99%

“…To enhance the performance of PCAs, researchers set their sights on the booming field of metamaterials which have the high design degree of freedom level and flexible manipulation capability. [ 7–9 ] A variety of metallic/dielectric nanostructures, such as gratings, [ 10–12 ] nanoislands, [ 13 ] hole arrays, [ 14 ] pillar arrays, [ 15–18 ] optical nanoantennas, [ 19 ] and interdigitated fingers, [ 20 ] have been integrated to PCAs to achieve outstanding characteristics. These nanostructures play positive roles primarily by altering the interaction of the femtosecond laser pulse and the substrate, thereby controlling the density and dynamics of the photogenerated carriers.…”

Section: Introductionmentioning

confidence: 99%

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Photoconductive Meta‐Antenna Enabling Terahertz Amplitude Spectrum Manipulation

Shi

Wang

et al. 2020

Advanced Photonics Research

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In recent years, as a promising new method, integrating nanostructures to improve the power of photoconductive antennas has received widespread attention. However, there are few reports on the application of artificial electromagnetic structures to regulate the spectral features of photoconductive antennas. Herein, it is demonstrated that by integrating split‐ring resonator (SRR)‐like metallic structures onto the coplanar lines of the photoconductive antenna transmitter, one can significantly manipulate the spectral feature of the generated terahertz (THz) radiation. The guided THz wave along the coplanar lines is scattered by the SRRs to the far field and interferes with the THz pulse radiated from the photoconductive antenna gap, leading to enhancement of the photoconductive antenna's energy and modulation in the spectrum. Further studies have shown that the strength, frequency, and band‐pass/band‐stop characteristics of the modulation can be altered by changing the geometry and placement of the SRRs. Water vapor absorption is also discussed to exemplify the benefit of this novel meta‐antenna over the ordinary photoconductive antenna in sensing scenario. The photoconductive antenna proposed here takes the lead in using artificial structures to manipulate the spectral domain behavior of photoconductive antennas, which is of great significance for THz spectroscopy, imaging, and sensing.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photoconductive Meta‐Antenna Enabling Terahertz Amplitude Spectrum Manipulation

Shi

Wang

et al. 2020

Advanced Photonics Research

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“…Many techniques have been developed to address this limitation [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Large-area photoconductive emitters based on plasmonic contact electrodes have been proposed to achieve high terahertz power levels [17].…”

Section: Introductionmentioning

confidence: 99%

Performance Enhancement of Photoconductive Antenna Using Saw-Toothed Plasmonic Contact Electrodes

et al. 2021

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A photoconductive logarithmic spiral antenna with saw-toothed plasmonic contact electrodes is proposed to provide a higher terahertz radiation compared with the conventional photoconductive antenna (PCA). The use of saw-toothed plasmonic contact electrodes creates a strong electric field between the anode and cathode, which generates a larger photocurrent and thereby effectively increases the terahertz radiation. The proposed PCA was fabricated and measured in response to an 80 fs optical pump from a fiber-based femtosecond laser with a wavelength of 780 nm. When the proposed antenna is loaded with an optical pump power of 20 mW and a bias voltage of 40 V, a broadband pulsed terahertz radiation in the frequency range of 0.1–2 THz was observed. Compared to the conventional PCA, the THz power measured by terahertz time domain spectroscopy (THz-TDS) increased by an average of 10.45 times.

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“…The terahertz (THz) frequency band (0.1-10 THz) in the electromagnetic spectrum had gained a lot of interest in the recent times owing to its usage in diversified applications such as noninvasive characterization and detection of materials using spectroscopy, [1][2][3] high data rate communication, and high quality sensing, imaging and detection applications in medical and security fields. [4][5][6][7][8] The underlying issues for the development of THz commercial solutions are related to the design of the cost-effective efficient THz sources and detectors which exhibits wideband, high directivity and sensitivity characteristics. 9 THz community preferred the photoconductive antennas (PCAs) and photometers as THz sources.…”

Section: Introductionmentioning

confidence: 99%

“…9 The THz radiations are generated from the PCA by illuminating the substrate with a photon source and applying the DC bias to the electrodes to accelerate the substrate charge carrier having an ultra-short lifetime. 4 To meet the aforementioned substrate requirements, the preferred choices for PCAs are LT-GaAs, [11][12][13] SI-GaAs, 13,14 and In-GaAs. 13,15 The suggested approaches for the enhancement of the IR coupling to PCA include antireflection coatings 16,17 and the usage of micro lens arrays.…”

Section: Introductionmentioning

confidence: 99%

Full wave numerical analysis of wideband and high directive log spiralTHzphotoconductive antenna

Dhiflaoui

Yahyaoui

Yousaf

et al. 2020

Int J Numerical Modelling

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This study presents, for the first time, a novel design of ultra-wideband (UWB), circularly polarized and highly directive log-spiral THz photoconductive antenna. The proposed antenna is simulated in High Frequency Structure Simulator using gold as the antenna electrode material which is backed by a quartz substrate (ε r = 3.78, tan δ = 0.0001) and hemispherical silicon-based lens with a diameter of 140 μm. A comprehensive detailed parametric study of the antenna design parameters is performed in the frequency range of 1 to 6 THz for the optimal design of the developed antenna structure. The optimal antenna structure with integrated lens has UWB characteristics with −10 dB impedance bandwidth of 5 THz and 3 dB axial ratio bandwidth of around 4 THz. The observed directivity and half-power beam width of the presented design varies in the range 5 to 12 dBi and 34 to 62 , respectively, for the frequency range of 1 to 4 THz. The wideband, high directivity as well as highefficiency (>50%) characteristics of the proposed design make it a favorable choice for the THz sensing and imaging applications.

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A Polarization-Resolved Study of Nanopatterned Photoconductive Antenna for Enhanced Terahertz Emission

Cited by 19 publications

References 43 publications

Photoconductive Meta‐Antenna Enabling Terahertz Amplitude Spectrum Manipulation

Photoconductive Meta‐Antenna Enabling Terahertz Amplitude Spectrum Manipulation

Performance Enhancement of Photoconductive Antenna Using Saw-Toothed Plasmonic Contact Electrodes

Full wave numerical analysis of wideband and high directive log spiralTHzphotoconductive antenna

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