Intense terahertz generation from photoconductive antennas

Abstract

In this paper, we review the past and recent works on generating intense terahertz (THz) pulses from photoconductive antennas (PCAs). We will focus on two types of large-aperture photoconductive antenna (LAPCA) that can generate high-intensity THz pulses (a) those with large-aperture dipoles and (b) those with interdigitated electrodes. We will first describe the principles of THz generation from PCAs. The critical parameters for improving the peak intensity of THz radiation from LAPCAs are summarized. We will then describe the saturation and limitation process of LAPCAs along with the advantages and disadvantages of working with wide-bandgap semiconductor substrates. Then, we will explain the evolution of LAPCA with interdigitated electrodes, which allows one to reduce the photoconductive gap size, and thus obtain higher bias fields while applying lower voltages. We will also describe recent achievements in intense THz pulses generated by interdigitated LAPCAs based on wide-bandgap semiconductors driven by amplified lasers. Finally, we will discuss the future perspectives of THz pulse generation using LAPCAs.

Graphical abstract

Keywords

sub-cycle intense terahertz (THz) pulses / ultrafast Ti:sapphire lasers / wide-bandgap semiconductors / large-aperture photoconductive antenna (LAPCA) / phase mask / interdigitated large-aperture photoconductive emitters (ILAPCA)

References

[1] Tonouchi M. Cutting-edge terahertz technology. Nature Photonics, 2007, 1: 97–105

[2] Consolino L, Bartalini S, De Natale P. Terahertz frequency metrology for spectroscopic applications: a review. Journal of Infrared, Millimeter and Terahertz Waves, 2017, 38(11): 1289–1315

[3] Nicoletti D, Cavalleri A. Nonlinear light–matter interaction at terahertz frequencies. Advances in Optics and Photonics, 2016, 8(3): 401

[4] Fausti D, Tobey R I, Dean N, Kaiser S, Dienst A, Hoffmann M C, Pyon S, Takayama T, Takagi H, Cavalleri A. Light-induced superconductivity in a stripe-ordered cuprate. Science, 2011, 331(6014): 189–191

[5] Först M, Tobey R I, Bromberger H, Wilkins S B, Khanna V, Caviglia A D, Chuang Y D, Lee W S, Schlotter W F, Turner J J, Minitti M P, Krupin O, Xu Z J, Wen J S, Gu G D, Dhesi S S, Cavalleri A, Hill J P. Melting of charge stripes in vibrationally driven La_1.875Ba_0.125CuO₄: assessing the respective roles of electronic and lattice order in frustrated superconductors. Physical Review Letters, 2014, 112(15): 157002

[6] Mankowsky R, Subedi A, Först M, Mariager S O, Chollet M, Lemke H T, Robinson J S, Glownia J M, Minitti M P, Frano A, Fechner M, Spaldin N A, Loew T, Keimer B, Georges A, Cavalleri A. Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa₂Cu₃O_6.5. Nature, 2014, 516(7529): 71–73

[7] Kaiser S, Clark S R, Nicoletti D, Cotugno G, Tobey R I, Dean N, Lupi S, Okamoto H, Hasegawa T, Jaksch D, Cavalleri A. Optical properties of a vibrationally modulated solid state Mott insulator. Scientific Reports, 2014, 4: 3823

[8] Mitrano M, Cantaluppi A, Nicoletti D, Kaiser S, Perucchi A, Lupi S, Di Pietro P, Pontiroli D, Riccò M, Clark S R, Jaksch D, Cavalleri A. Possible light-induced superconductivity in K₃C₆₀ at high temperature. Nature, 2016, 530(7591): 461–464

[9] Zhang X C, Shkurinov A, Zhang Y. Extreme terahertz science. Nature Photonics, 2017, 11: 16–18

[10] Matsunaga R, Tsuji N, Fujita H, Sugioka A, Makise K, Uzawa Y, Terai H, Wang Z, Aoki H, Shimano R. Light-induced collective pseudospin precession resonating with Higgs mode in a superconductor. Science, 2014, 345(6201): 1145–1149

[11] Matsunaga R, Hamada Y I, Makise K, Uzawa Y, Terai H, Wang Z, Shimano R. Higgs amplitude mode in the BCS superconductors Nb_1−xTi_xN induced by terahertz pulse excitation. Physical Review Letters, 2013, 111(5): 057002

[12] Rajasekaran S, Casandruc E, Laplace Y, Nicoletti D, Gu G D, Clark S R, Jaksch D, Cavalleri A. Parametric amplification of a superconducting plasma wave. Nature Physics, 2016, 12(11): 1012–1016

[13] Auston D H, Cheung K P, Smith P R. Picosecond photoconducting Hertzian dipoles. Applied Physics Letters, 1984, 45(3): 284–286

[14] Darrow J T, Zhang X C, Auston D H, Morse J D. Saturation properties of large-aperture photoconducting antennas. IEEE Journal of Quantum Electronics, 1992, 28(6): 1607–1616

[15] Stone M R, Naftaly M, Miles R E, Fletcher J R, Steenson D P. Electrical and radiation characteristics of semilarge photoconductive terahertz emitters. IEEE Transactions on Microwave Theory and Techniques, 2004, 52(10): 2420–2429

[16] Reid M, Fedosejevs R. Quantitative comparison of terahertz emission from (100) InAs surfaces and a GaAs large-aperture photoconductive switch at high fluences. Applied Optics, 2005, 44(1): 149–153

[17] Grischkowsky D, Keiding S, van Exter M, Fattinger C. Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors. Journal of the Optical Society of America B, Optical Physics, 1990, 7(10): 2006

[18] Hafez H A, Chai X, Ibrahim A, Mondal S, Férachou D, Ropagnol X, Ozaki T. Intense terahertz radiation and their applications. Journal of Optics, 2016, 18(9): 093004

[19] Ulbricht R, Hendry E, Shan J, Heinz T F, Bonn M. Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy. Reviews of Modern Physics, 2011, 83(2): 543–586

[20] Pačebutas V, Bičiūnas A, Balakauskas S, Krotkus A, Andriukaitis G, Lorenc D, Pugžlys A, Baltuška A. Terahertz time-domain-spectroscopy system based on femtosecond Yb:fiber laser and GaBiAs photoconducting component. Applied Physics Letters, 2010, 97(3): 031111

[21] Rungsawang R, Ohta K, Tukamoto K, Hattori T. Ring formation of focused half-cycle terahertz pulses. Journal of Physics D, Applied Physics, 2003, 36(3): 229

[22] Razzari L, Su F H, Sharma G, Blanchard F, Ayesheshim A, Bandulet H C, Morandotti R, Kieffer J C, Ozaki T, Reid M, Hegmann F A. Nonlinear ultrafast modulation of the optical absorption of intense few-cycle terahertz pulses in n-doped semiconductors. Physical Review B: Condensed Matter and Materials Physics, 2009, 79(19): 193204

[23] Hu B B, Nuss M C. Imaging with terahertz waves. Optics Letters, 1995, 20(16): 1716

[24] Mittleman D M, Gupta M, Neelamani R, Baraniuk R G, Rudd J V, Koch M. Recent advances in terahertz imaging. Applied Physics B, Lasers and Optics, 1999, 68(6): 1085–1094

[25] Jiang Z, Zhang X C. Single-shot spatiotemporal terahertz field imaging. Optics Letters, 1998, 23(14): 1114–1116

[26] O’Hara J, Grischkowsky D. Quasi-optic terahertz imaging. Optics Letters, 2001, 26(23): 1918–1920

[27] Zeitler J A, Gladden L F. In-vitro tomography and non-destructive imaging at depth of pharmaceutical solid dosage forms. European Journal of Pharmaceutics and Biopharmaceutics, 2009, 71(1): 2–22

[28] Jepsen P U, Cooke D G, Koch M. Terahertz spectroscopy and imaging-modern techniques and applications. Laser & Photonics Reviews, 2011, 5(1): 124–166

[29] Yang S H, Hashemi M R, Berry C W, Jarrahi M. 7.5% optical-to-terahertz conversion efficiency offered by photoconductive emitters with three-dimensional plasmonic contact electrodes. IEEE Transactions on Terahertz Science and Technology, 2014, 4(5): 575–581

[30] Yardimci N T, Lu H, Jarrahi M. High power telecommunication-compatible photoconductive terahertz emitters based on plasmonic nano-antenna arrays. Applied Physics Letters, 2016, 109(19): 191103

[31] Yardimci N T, Cakmakyapan S, Hemmati S, Jarrahi M. Significant efficiency enhancement in photoconductive terahertz emitters through three-dimensional light confinement. In: Proceedings of IEEE MTT-S International Microwave Symposium. Honololu: IEEE, 2017, 435–438

[32] Yardimci N T, Cakmakyapan S, Hemmati S, Jarrahi M. A high-power broadband terahertz source enabled by three-dimensional light confinement in a plasmonic nanocavity. Scientific Reports, 2017, 7(1): 4166

[33] Jones R R, You D, Bucksbaum P H. Ionization of Rydberg atoms by subpicosecond half-cycle electromagnetic pulses. Physical Review Letters, 1993, 70(9): 1236–1239

[34] Ropagnol X, Khorasaninejad M, Raeiszadeh M, Safavi-Naeini S, Bouvier M, Côté C Y, Laramée A, Reid M, Gauthier M A, Ozaki T. Intense THz pulses with large ponderomotive potential generated from large aperture photoconductive antennas. Optics Express, 2016, 24(11): 11299–11311

[35] Ropagnol X, Kovács Z, Gilicze B, Zhuldybina M, Blanchard F, Garcia-Rosas C M, Szatmári S, Földes I B, Ozaki T. Intense sub-terahertz radiation from wide-bandgap semiconductor based large-aperture photoconductive antennas pumped by UV lasers. New Journal of Physics, 2019, 21(11): 113042

[36] Fülöp J A, Tzortzakis S, Kampfrath T. Laser-driven strong-field terahertz sources. Advanced Optical Materials, 2020, 8(3): 1900681

[37] Kampfrath T, Tanaka K, Nelson K A. Resonant and nonresonant control over matter and light by intense terahertz transients. Nature Photonics, 2013, 7: 680–690

[38] Ropagnol X, Morandotti R, Ozaki T, Reid M. THz pulse shaping and improved optical-to-THz conversion efficiency using a binary phase mask. Optics Letters, 2011, 36(14): 2662–2664

[39] You D, Dykaar D R, Jones R R, Bucksbaum P H. Generation of high-power sub-single-cycle 500-fs electromagnetic pulses. Optics Letters, 1993, 18(4): 290

[40] Brown E R, Smith F W, McIntosh K A. Coherent millimeter-wave generation by heterodyne conversion in low-temperature-grown GaAs photoconductors. Journal of Applied Physics, 1993, 73(3): 1480–1484

[41] Emadi R, Barani N, Safian R, Nezhad A Z. Hybrid computational simulation and study of terahertz pulsed photoconductive antennas. Journal of Infrared, Millimeter and Terahertz Waves, 2016, 37(11): 1069–1085

[42] Kim D S, Citrin D S. Coulomb and radiation screening in photoconductive terahertz sources. Applied Physics Letters, 2006, 88(16): 161117

[43] Tiedje H F, Saeedkia D, Nagel M, Haugen H K. Optical scanning techniques for characterization of terahertz photoconductive antenna arrays. In: Proceedings of the 33rd International Conference on Infrared and Millimeter Waves and the 16th International Conference on Terahertz Electronics. Pasadena: IEEE, 2008, 1–2

[44] Hou L, Shi W. An LT-GaAs terahertz photoconductive antenna with high emission power, low noise, and good stability. IEEE Transactions on Electron Devices, 2013, 60(5): 1619–1624

[45] Huang Y, Khiabani N, Shen Y, Li D. Terahertz photoconductive antenna efficiency. In: Proceedings of 2011 International Workshop on Antenna Technology (iWAT). Hong Kong: IEEE, 2011, 152–156

[46] Burford N M, El-Shenawee M O. Review of terahertz photoconductive antenna technology. Optical Engineering (Redondo Beach, Calif.), 2017, 56(1): 010901

[47] Tani M, Matsuura S, Sakai K, Nakashima S. Emission characteristics of photoconductive antennas based on low-temperature-grown GaAs and semi-insulating GaAs. Applied Optics, 1997, 36(30): 7853–7859

[48] Tani M, Yamamoto K, Estacio E S, Que C T, Nakajima H, Hibi M, Miyamaru F, Nishizawa S, Hangyo M. Photoconductive emission and detection of terahertz pulsed radiation using semiconductors and semiconductor devices. Journal of Infrared, Millimeter and Terahertz Waves, 2012, 33(4): 393–404

[49] Shi W, Hou L, Wang X. High effective terahertz radiation from semi-insulating-GaAs photoconductive antennas with ohmic contact electrodes. Journal of Applied Physics, 2011, 110(2): 023111

[50] Benicewicz P K, Taylor A J. Scaling of terahertz radiation from large-aperture biased InP photoconductors. Optics Letters, 1993, 18(16): 1332

[51] Ropagnol X, Morandotti R, Ozaki T, Reid M. Toward high-power terahertz emitters using large aperture ZnSe photoconductive antennas. IEEE Photonics Journal, 2011, 3(2): 174–186

[52] Prajapati J, Bharadwaj M, Chatterjee A, Bhattacharjee R. Magnetic field-assisted radiation enhancement from a large aperture photoconductive antenna. IEEE Transactions on Microwave Theory and Techniques, 2018, 66(2): 678–687

[53] Ropagnol X. Développement d’une source de radiation terahertz (THz) intense et mise en forme d’impulsions THz àpartir d’une antenne de grande ouverture de ZnSe. 2013

[54] Wang X, Shi W, Hou L, Ma D, Qu G. Investigation of semi-insulating gallium arsenide photoconductive photodetectors. In: Proceedings of 2008 International Conference on Optical Instruments and Technology: Advanced Sensor Technologies and Applications. Beijing: SPIE, 2008, 71570B

[55] Yoneda H, Tokuyama K, Ueda K, Yamamoto H, Baba K. High-power terahertz radiation emitter with a diamond photoconductive switch array. Applied Optics, 2001, 40(36): 6733–6736

[56] Meng P, Zhao X, Yang X, Wu J, Xie Q, He J, Hu J, He J. Breakdown phenomenon of ZnO varistors caused by non-uniform distribution of internal pores. Journal of the European Ceramic Society, 2019, 39(15): 4824–4830

[57] Singh B P, Imafuji O, Hirose Y, Fukushima Y, Takigawa S, Ueda D. High power C-doped GaN photoconductive THz emitter. In: Proceedings of Joint 32nd International Conference on Infrared and Millimetre Waves, and 15th International Conference on Terahertz Electronics. Cardiff: IEEE, 2007, 1004–1005

[58] Ropagnol X, Morandotti R, Ozaki T, Reid M. Towards high-power terahertz emitters using large aperture ZnSe photoconductive antennas. In: Proceedings of Laser Science to Photonic Applications. San Jose: IEEE, 2010, 1–2

[59] Doğan S, Teke A, Huang D, Morkoç H, Roberts C B, Parish J, Ganguly B, Smith M, Myers R E, Saddow S E. 4H-SiC photoconductive switching devices for use in high-power applications. Applied Physics Letters, 2003, 82(18): 3107–3109

[60] Friedrichs P, Burte E P, Schörner R. Dielectric strength of thermal oxides on 6H-SiC and 4H-SiC. Applied Physics Letters, 1994, 65(13): 1665–1667

[61] Imafuji O, Singh B P, Hirose Y, Fukushima Y, Takigawa S. High power subterahertz electromagnetic wave radiation from GaN photoconductive switch. Applied Physics Letters, 2007, 91(7): 071112

[62] Wang L M. Relationship between intrinsic breakdown field and bandgap of materials. In: Proceedings of the 25th International Conference on Microelectronics. Belgrade: IEEE, 2006, 615–618

[63] Ropagnol X, Bouvier M, Reid M, Ozaki T. Improvement in thermal barriers to intense terahertz generation from photoconductive antennas. Journal of Applied Physics, 2014, 116(4): 043107

[64] Hou L, Shi W, Chen S. Noise analysis and optimization of terahertz photoconductive emitters. IEEE Journal of Selected Topics in Quantum Electronics, 2013, 19(1): 8401305

[65] Moreno E, Pantoja M F, Ruiz F G, Roldán J B, García S G. On the numerical modeling of terahertz photoconductive antennas. Journal of Infrared, Millimeter and Terahertz Waves, 2014, 35(5): 432–444

[66] Castro-Camus E, Fu L, Lloyd-Hughes J, Tan H H, Jagadish C, Johnston M B. Photoconductive response correction for detectors of terahertz radiation. Journal of Applied Physics, 2008, 104(5): 053113

[67] Park S G, Weiner A M, Melloch M R, Siders C W, Siders J L W, Taylor A J. High-power narrow-band terahertz generation using large-aperture photoconductors. IEEE Journal of Quantum Electronics, 1999, 35(8): 1257–1268

[68] Benicewicz P K, Roberts J P, Taylor A J. Scaling of terahertz radiation from large-aperture biased photoconductors. Journal of the Optical Society of America B, Optical Physics, 1994, 11(12): 2533

[69] Duvillaret L, Garet F, Roux J F, Coutaz J L. Analytical modeling and optimization of terahertz time-domain spectroscopy experiments using photoswitches as antennas. IEEE Journal of Selected Topics in Quantum Electronics, 2001, 7(4): 615–623

[70] Castro-Camus E, Lloyd-Hughes J, Johnston M B. Three-dimensional carrier-dynamics simulation of terahertz emission from photoconductive switches. Physical Review B: Condensed Matter and Materials Physics, 2005, 71(19): 195301

[71] Prajapati J, Bharadwaj M, Chatterjee A, Bhattacharjee R. Radiation field analysis of a photoconductive antenna using an improved carrier dynamics. Semiconductor Science and Technology, 2019, 34(2): 024004

[72] Piao Z, Tani M, Sakai K. Carrier dynamics and terahertz radiation in photoconductive antennas. Japanese Journal of Applied Physics, 2000, 39(1): 96–100

[73] Winnerl S, Peter F, Nitsche S, Dreyhaupt A, Zimmermann B, Wagner M, Schneider H, Helm M, Köhler K. Generation and detection of THz radiation with scalable antennas based on GaAs substrates with different carrier lifetimes. IEEE Journal of Selected Topics in Quantum Electronics, 2008, 14(2): 449–457

[74] Shi W, Sun X F, Zeng J, Jia W L. Carrier dynamics and terahertz radiation in large-aperture photoconductive antenna. In: Proceedings of International Symposium on Photoelectronic Detection and Imaging 2007: Laser, Ultraviolet, and Terahertz Technology. Beijing: SPIE, 2008, 662228

[75] Liu D, Qin J. Carrier dynamics of terahertz emission from low-temperature-grown GaAs. Applied Optics, 2003, 42(18): 3678–3683

[76] Piao Z, Tani M, Sakai K. Carrier dynamics and THz radiation in biased semiconductor structures. In: Proceedings of SPIE 3617, Terahertz Spectroscopy and Applications. San Jose: SPIE, 1999, 49–56

[77] Chen L, Fan W. Numerical simulation of terahertz generation and detection based on ultrafast photoconductive antennas. In: Proceedings of International Symposium on Photoelectronic Detection and Imaging 2011: Terahertz Wave Technologies and Applications. Beijing: SPIE, 2011, 81950K

[78] Šlekas G, Kancleris Ž, Urbanowicz A, Čiegis R. Comparison of full-wave models of terahertz photoconductive antenna based on ordinary differential equation and Monte Carlo method. European Physical Journal Plus, 2020, 135(1): 85

[79] Cadilhon B, Cassany B, Modin P, Diot J C, Bertrand V, Pecastaing L. Ultra Wideband Antennas for High Pulsed Power Applications. In: Matin M, ed. Ultra Wideband Communications: Novel Trends–Antennas and Propagation. Rijeka: InTech, 2011

[80] Mahadevan S, Hardas S M, Suryan G. Electrical breakdown in semiconductors. Physica Status Solidi (a), 1971, 8(2): 335–374

[81] Xu M, Li M, Shi W, Ma C, Zhang Q, Fan L, Shang X, Xue P. Temperature-dependence of high-gain operation in GaAs photoconductive semiconductor switch at 1.6 mJ excitation. IEEE Electron Device Letters, 2016, 37(1): 67–69

[82] Qadri S B, Wu D H, Graber B D, Mahadik N A, Garzarella A. Failure mechanism of THz GaAs photoconductive antenna. Applied Physics Letters, 2012, 101(1): 011910

[83] Sun C, Zhang A. Efficient terahertz generation from lightly ion-beam-treated semi-insulating GaAs photoconductive antennas. Applied Physics Express, 2017, 10(10): 102202

[84] Gupta S, Frankel M Y, Valdmanis J A, Whitaker J F, Mourou G A, Smith F W, Calawa A R. Subpicosecond carrier lifetime in GaAs grown by molecular beam epitaxy at low temperatures. Applied Physics Letters, 1991, 59(25): 3276–3278

[85] Liu T A, Tani M, Nakajima M, Hangyo M, Pan C L. Ultrabroadband terahertz field detection by photoconductive antennas based on multi-energy arsenic-ion-implanted GaAs and semi-insulating GaAs. Applied Physics Letters, 2003, 83(7): 1322–1324

[86] Salem B, Morris D, Aimez V, Beerens J, Beauvais J, Houde D. Pulsed photoconductive antenna terahertz sources made on ion-implanted GaAs substrates. Journal of Physics Condensed Matter, 2005, 17(46): 7327

[87] Salem B, Morris D, Salissou Y, Aimez V, Charlebois S, Chicoine M, Schiettekatte F. Terahertz emission properties of arsenic and oxygen ion-implanted GaAs based photoconductive pulsed sources. Journal of Vacuum Science & Technology A, Vacuum, Surfaces, and Films, 2006, 24(3): 774–777

[88] Ono S, Murakami H, Quema A, Diwa G, Sarukura N, Nagasaka R, Ichikawa Y, Ogino H, Ohshima E, Yoshikawa A, Fukuda T. Generation of terahertz radiation using zinc oxide as photoconductive material excited by ultraviolet pulses. Applied Physics Letters, 2005, 87(26): 261112

[89] Beck M, Schäfer H, Klatt G, Demsar J, Winnerl S, Helm M, Dekorsy T. Impulsive terahertz radiation with high electric fields from an amplifier-driven large-area photoconductive antenna. Optics Express, 2010, 18(9): 9251–9257

[90] Gavrushchuk E M. Polycrystalline zinc selenide for IR optical applications. Inorganic Materials, 2003, 39(9): 883–899

[91] Cho P S, Peng F, Ho P T, Goldhar J, Lee C H. ZnSe photoconductive switches with transparent electrodes. In: Proceedings of the 8th IEEE International Conference on Pulsed Power. San Diego: IEEE, 2005, 209–212

[92] Ho P T, Peng F, Goldhar J. Photoconductive switching using polycrystalline ZnSe. IEEE Transactions on Electron Devices, 1990, 37(12): 2517–2519

[93] Cho P S, Goldhar J, Lee C H, Saddow S E, Neudeck P. Photoconductive and photovoltaic response of high-dark-resistivity 6H-SiC devices. Journal of Applied Physics, 1995, 77(4): 1591–1599

[94] Holzman J F, Elezzabi A Y. Two-photon photoconductive terahertz generation in ZnSe. Applied Physics Letters, 2003, 83(14): 2967–2969

[95] Mauch D, Sullivan W, Bullick A, Neuber A, Dickens J. High power lateral silicon carbide photoconductive semiconductor switches and investigation of degradation mechanisms. IEEE Transactions on Plasma Science, 2015, 43(6): 2021–2031

[96] Shimizu H, Watanabe N, Morikawa T, Shima A, Iwamuro N. 1.2 kV silicon carbide Schottky barrier diode embedded MOSFETs with extension structure and titanium-based single contact. Japanese Journal of Applied Physics, 2020, 59(2): 026502

[97] Kimoto T, Yonezawa Y. Current status and perspectives of ultrahigh-voltage SiC power devices. Materials Science in Semiconductor Processing, 2018, 78: 43–56

[98] Bhalla A. Status of SiC Products and Technology. In: Sharma Y, ed. Disruptive Wide Bandgap Semiconductors, Related Technologies, and Their Applications. London: InTech, 2018

[99] Xiao L, Yang X, Duan P, Xu H, Chen X, Hu X, Peng Y, Xu X. Effect of electron avalanche breakdown on a high-purity semi-insulating 4H-SiC photoconductive semiconductor switch under intrinsic absorption. Applied Optics, 2018, 57(11): 2804–2808

[100] Yu D, Kang J, Berakdar J, Jia C. Nondestructive ultrafast steering of a magnetic vortex by terahertz pulses. NPG Asia Materials, 2020, 12(1): 36

[101] Elliott D. Ultraviolet Laser Technology and Applications. New York: Academic Press, 2014

[102] Duarte F. Tunable Lasers Handbook. New York: Academic Press,1996

[103] Szatmári S, Rácz B, Schäffer F P. Bandwidth limited amplification of 220 fs pulses in XeCl. Optics Communications, 1987, 62(4): 271–276

[104] Dick B, Szatmári S, Rácz B, Schäfer F P. Bandwidth limited amplification of 220 fs pulses in XeCl: theoretical and experimental study of temporal and spectral behavior. Optics Communications, 1987, 62(4): 277–283

[105] Szatmári S, Schäfer F P, Müller-Horsche E, Müchenheim W. Hybrid dye-excimer laser system for the generation of 80 fs, 900 GW pulses at 248 nm. Optics Communications, 1987, 63(5): 305–309

[106] Di G, Bhattacharya A, Samad S, Nayak B, Shah A P, Rahman A A, Bhattacharya A, Prabhu S S. Towards bandwidth-enhanced GaN-based terahertz photoconductive antennas. In: Proceedings of the 44th International Conference on Infrared, Millimeter, and Terahertz Waves. Paris: IEEE, 2019, 1–2

[107] Szatmári S. High-brightness ultraviolet excimer lasers. Applied Physics B: Laser and Optics, 1994, 58(3): 211–223

[108] Loata G C, Thomson M D, Löffler T, Roskos H G. Radiation field screening in photoconductive antennae studied via pulsed terahertz emission spectroscopy. Applied Physics Letters, 2007, 91(23): 232506

[109] Budiarto E, Margolies J, Jeong S, Son J, Bokor J. High-intensity terahertz pulses at 1-kHz repetition rate. IEEE Journal of Quantum Electronics, 1996, 32(10): 1839–1846

[110] Welsh G H, Turton D A, Jones D R, Jaroszynski D A, Wynne K. 200 ns pulse high-voltage supply for terahertz field emission. Review of Scientific Instruments, 2007, 78(4): 043103

[111] Winnerl S, Zimmermann B, Peter F, Schneider H, Helm M. Terahertz Bessel-Gauss beams of radial and azimuthal polarization from microstructured photoconductive antennas. Optics Express, 2009, 17(3): 1571–1576

[112] Cliffe M J, Rodak A, Graham D M, Jamison S P. Generation of longitudinally polarized terahertz pulses with field amplitudes exceeding 2 kV/cm. Applied Physics Letters, 2014, 105(19): 191112

[113] .,Mourou G A, Bloom D M, Lee C H. Picosecond electronics and optoelectronics. In: Proceedings of the Topical Meeting Lake Tahoe. Nevada: SPIE, 1985, 438

[114] Cox C H III, Diadiuk V, Yao I, Leonberger F J, Williamson R C. InP optoelectronic switches and their high-speed signal-processiny applications. In: Proceedings of Picosecond Optoelectronics. San Diego: SPIE, 1983, 164–168

[115] Hattori T, Egawa K, Ookuma S I, Itatani T. Intense terahertz pulses from large-aperture antenna with interdigitated electrodes. Japanese Journal of Applied Physics, 2006, 45(15): L422–L424

[116] Chou S Y, Liu Y, Fischer P B. Tera-hertz GaAs metal-semiconductor-metal photodetectors with 25 nm finger spacing and finger width. Applied Physics Letters, 1992, 61(4): 477–479

[117] Awad M, Nagel M, Kurz H, Herfort J, Ploog K. Characterization of low temperature GaAs antenna array terahertz emitters. Applied Physics Letters, 2007, 91(18): 181124

[118] Acuna G, Buersgens F, Lang C, Handloser M, Guggenmos A, Kersting R. Interdigitated terahertz emitters. Electronics Letters, 2008, 44(3): 229–231

[119] Ropagnol X, Blanchard F, Ozaki T, Reid M. Intense terahertz generation at low frequencies using an interdigitated ZnSe large aperture photoconductive antenna. Applied Physics Letters, 2013, 103(16): 161108

[120] Dreyhaupt A, Winnerl S, Dekorsy T, Helm M. High-intensity terahertz radiation from a microstructured large-area photoconductor. Applied Physics Letters, 2005, 86(12): 121114

[121] Go D B, Pohlman D A. A mathematical model of the modified Paschen’s curve for breakdown in microscale gaps. Journal of Applied Physics, 2010, 107(10): 103303

[122] Headley C, Fu L, Member S, Parkinson P, Xu X, Lloyd-Hughes J, Jagadish C, Johnston M B. Improved performance of GaAs-based terahertz emitters via surface passivation and silicon nitride encapsulation. IEEE Journal of Selected Topics in Quantum Electronics, 2011, 17(1): 17–21

[123] Gupta A, Rana G, Bhattacharya A, Singh A, Jain R, Bapat R D, Duttagupta S P, Prabhu S S. Enhanced optical-to-THz conversion efficiency of photoconductive antenna using dielectric nano-layer encapsulation. APL Photonics, 2018, 3(5): 051706

[124] Kirawanich P, Yakura S J, Islam N E. Study of high-power wideband terahertz-pulse generation using integrated high-speed photoconductive semiconductor switches. IEEE Transactions on Plasma Science, 2009, 37(1): 219–228

[125] Singh A, Welsch M, Winnerl S, Helm M, Schneider H. Improved electrode design for interdigitated large-area photoconductive terahertz emitters. Optics Express, 2019, 27(9): 13108–13115

[126] Ropagnol X, Chai X, Raeis-Zadeh S M, Safavi-Naeini S, Kirouac-Turmel M, Bouvier M, Cote C Y, Reid M, Gauthier M A, Ozaki T. Influence of gap size on intense THz generation from ZnSe interdigitated large aperture photoconductive antennas. IEEE Journal of Selected Topics in Quantum Electronics, 2017, 23(4): 1–8

[127] Berry C W, Jarrahi M. Principles of impedance matching in photoconductive antennas. Journal of Infrared, Millimeter and Terahertz Waves, 2012, 33(12): 1182–1189

[128] Emadi R, Safian R, Nezhad A Z. Theoretical modeling of terahertz pulsed photoconductive antennas based on hot-carriers effect. IEEE Journal of Selected Topics in Quantum Electronics, 2017, 23(4): 1–9

[129] Brown E R, McIntosh K A, Smith F W, Nichols K B, Manfra M J, Dennis C L, Mattia J P. Milliwatt output levels and superquadratic bias dependence in a low-temperature-grown GaAs photomixer. Applied Physics Letters, 1994, 64(24): 3311–3313

[130] Ropagnol X, Blanchard F, Ozaki T, Reid M. Intense terahertz generation at low frequencies using an interdigitated ZnSe large aperture photoconductive antenna. Applied Physics Letters, 2013, 103(16): 161108

[131] Bacon D R, Gill T B, Rosamond M, Burnett A D, Dunn A, Li L, Linfield E H, Davies A G, Dean P, Freeman J R. Photoconductive arrays on insulating substrates for high-field terahertz generation. Optics Express, 2020, 28(12): 17219–17231

[132] Dreyhaupt A, Peter F, Winnerl S, Nitsche S, Wagner M, Schneider H, Helm M, Köhler K. Leistungsstarke emitter und einfach handhabbare detektoren für die terahertz-time-domain-spektroskopie. Technisches Messen., 2008, 75(1): 3–13

[133] Winnerl S. Scalable microstructured photoconductive terahertz emitters. Journal of Infrared, Millimeter and Terahertz Waves, 2012, 33(4): 431–454

[134] Matthäus G, Nolte S, Hohmuth R, Voitsch M, Richter W, Pradarutti B, Riehemann S, Notni G, Tünnermann A. Large-area microlens emitters for powerful THz emission. Applied Physics B, Lasers and Optics, 2009, 96(2–3): 233–235

[135] Singh A, Prabhu S S. Microlensless interdigitated photoconductive terahertz emitters. Optics Express, 2015, 23(2): 1529–1535

[136] Bacon D R, Gill T B, Rosamond M, Burnett A D, Dunn A, Li L, Linfield E H, Davies A G, Dean P, Freeman J R. Photoconductive arrays on insulating substrates for high-field terahertz generation. Optics Express, 2020, 28(12): 17219–17231

[137] Singh A, Winnerl S, König-Otto J C, Stephan D R, Helm M, Schneider H. Plasmonic efficiency enhancement at the anode of strip line photoconductive terahertz emitters. Optics Express, 2016, 24(20): 22628–22634

[138] Zhang X C. Generation and detection of terahertz electromagnetic pulses from semiconductors with femtosecond optics. Journal of Luminescence, 1995, 66–67(1–6): 488–492

[139] Preu S, Dhler G H, Malzer S, Wang L J, Gossard A C. Tunable, continuous-wave terahertz photomixer sources and applications. Journal of Applied Physics, 2011, 109(6): 061301

[140] Hale P J, Madeo J, Chin C, Dhillon S S, Mangeney J, Tignon J, Dani K M. 20 THz broadband generation using semi-insulating GaAs interdigitated photoconductive antennas. Optics Express, 2014, 22(21): 26358–26364

[141] Madéo J, Jukam N, Oustinov D, Rosticher M, Rungsawang R, Tignon J, Dhillon S S. Frequency tunable terahertz interdigitated photoconductive antennas. Electronics Letters, 2010, 46(9): 611–613

[142] Yardimci N T, Yang S H, Berry C W, Jarrahi M. High-power terahertz generation using large-area plasmonic photoconductive emitters. IEEE Transactions on Terahertz Science and Technology, 2015, 5(2): 223–229

[143] Maussang K, Palomo J, Mangeney J, Dhillon S S, Tignon J. Large-area photoconductive switches as emitters of terahertz pulses with fully electrically controlled linear polarization. Optics Express, 2019, 27(10): 14784–14797

[144] Sterczewski L A, Grzelczak M P, Plinski E F. Terahertz antenna electronic chopper. Review of Scientific Instruments, 2016, 87(1): 014702

[145] Hirori H, Doi A, Blanchard F, Tanaka K. Single-cycle terahertz pulses with amplitudes exceeding 1 MV/cm generated by optical rectification in LiNbO₃. Applied Physics Letters, 2011, 98(9): 091106

[146] Chai X, Ropagnol X, Raeis-Zadeh S M, Reid M, Safavi-Naeini S, Ozaki T. Subcycle terahertz nonlinear optics. Physical Review Letters, 2018, 121(14): 143901

[147] Moreno E, Pantoja M F, Ruiz F G, Roldán J B, García S G. On the numerical modeling of terahertz photoconductive antennas. Journal of Infrared, Millimeter and Terahertz Waves, 2014, 35(5): 432–444

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