Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9566850
Md Tasnim Munshi, P. Klarskov
We study the influence of resonant gold nanorod deposited on an InAs surface to enhance the terahertz (THz) emission induced by the photo-Dember effect. With the nanorods forming a coffee-stain ring, we observe a variation in the induced THz field, which we image with Laser THz Emission Microscopy (LTEM). Here, we observe an enhancement of up to 30% of the THz signal measured from a bare InAs surface. On the other hand, clustering of nanorods in the central region leads to a suppression of THz signal where less than 80% of the signal measured from the bare surface is obtained. By preparing several samples with the same method but varying the number of nanorods, we are able to study the correlation between the nanorod concentration and the THz signal enhancement.
{"title":"Laser Terahertz Emission Microscopy of Gold Nanorods forming a Coffee-stain Ring on a Semiconductor Surface","authors":"Md Tasnim Munshi, P. Klarskov","doi":"10.1109/IRMMW-THz50926.2021.9566850","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9566850","url":null,"abstract":"We study the influence of resonant gold nanorod deposited on an InAs surface to enhance the terahertz (THz) emission induced by the photo-Dember effect. With the nanorods forming a coffee-stain ring, we observe a variation in the induced THz field, which we image with Laser THz Emission Microscopy (LTEM). Here, we observe an enhancement of up to 30% of the THz signal measured from a bare InAs surface. On the other hand, clustering of nanorods in the central region leads to a suppression of THz signal where less than 80% of the signal measured from the bare surface is obtained. By preparing several samples with the same method but varying the number of nanorods, we are able to study the correlation between the nanorod concentration and the THz signal enhancement.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"1 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73853933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We numerically generate the terahertz circular Airy beams(THz-CABs) with the power-exponent-phase(PEP) vertices. We demonstrate the combination of the PEP vertices and THz-CABs for the extension application of PEP vertices. At the same time, the light path of THz-CABs will be more compact and simpler compared with the optical one.
{"title":"Terahertz circular Airy beams carrying power-exponent-phase vortices","authors":"Qian Huang, Mengting Zhang, Siyu Tu, Kejia Wang, Zhengang Yang, Jinsong Liu","doi":"10.1109/IRMMW-THz50926.2021.9567280","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567280","url":null,"abstract":"We numerically generate the terahertz circular Airy beams(THz-CABs) with the power-exponent-phase(PEP) vertices. We demonstrate the combination of the PEP vertices and THz-CABs for the extension application of PEP vertices. At the same time, the light path of THz-CABs will be more compact and simpler compared with the optical one.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"48 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73950581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567101
M. Vahdani, M. Fakhari, N. H. Matlis, F. Kärtner
We present the design of a THz driven booster which is capable of accelerating electrons from 55 keV up to above 430 keV kinetic energy. This device is a 3-layer segmented structure and requires a 400-µJ single-cycle THz pulse with center frequency at 300 GHz. Sensitivity of the output beam dynamics to the input parameters and manufacturing tolerances of the booster is also investigated in this paper.
{"title":"Design and sensitivity analysis of a single sided pumped THz booster","authors":"M. Vahdani, M. Fakhari, N. H. Matlis, F. Kärtner","doi":"10.1109/IRMMW-THz50926.2021.9567101","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567101","url":null,"abstract":"We present the design of a THz driven booster which is capable of accelerating electrons from 55 keV up to above 430 keV kinetic energy. This device is a 3-layer segmented structure and requires a 400-µJ single-cycle THz pulse with center frequency at 300 GHz. Sensitivity of the output beam dynamics to the input parameters and manufacturing tolerances of the booster is also investigated in this paper.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"284 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74368495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567192
Xipu Dong, Jierong Cheng, Shengjiang Chang
Growing attention has been paid to multifunctional metasurfaces due to the compactness and the flexibility in beam manipulation. A bi-functional metagrating capable of anomalous refraction and beam splitting via asymmetric diffraction is designed, 3D-printed and experimentally verified at 0.14 THz. The asymmetric diffraction behavior is well explained by the excitation-direction-dependent mode amplitude inside the metagrating based on a simplified modal method. The measured efficiency of anomalous refraction towards +70° is 80.7% under +z illumination, and the measured efficiency of beam splitting is 43.7%/39.5% towards -70°/+70° under –z illumination. Our work opens a new avenue in developing multifunctional and compact terahertz devices for wavefront shaping via excitation directions.
{"title":"An Efficient Bi-functional Metagrating via Asymmetric Diffraction of Terahertz Beams","authors":"Xipu Dong, Jierong Cheng, Shengjiang Chang","doi":"10.1109/IRMMW-THz50926.2021.9567192","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567192","url":null,"abstract":"Growing attention has been paid to multifunctional metasurfaces due to the compactness and the flexibility in beam manipulation. A bi-functional metagrating capable of anomalous refraction and beam splitting via asymmetric diffraction is designed, 3D-printed and experimentally verified at 0.14 THz. The asymmetric diffraction behavior is well explained by the excitation-direction-dependent mode amplitude inside the metagrating based on a simplified modal method. The measured efficiency of anomalous refraction towards +70° is 80.7% under +z illumination, and the measured efficiency of beam splitting is 43.7%/39.5% towards -70°/+70° under –z illumination. Our work opens a new avenue in developing multifunctional and compact terahertz devices for wavefront shaping via excitation directions.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"66 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74575682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567317
Mingxiang Stephen Li, S. Suzuki, C. Fumeaux, W. Withayachumnankul
Resonant-tunneling diodes (RTDs) are promising candidates for terahertz sources but typically exhibit an unexpected large tilt angle in the main lobe of their radiation pattern. In this paper, we present two types of planar metallic arrays, a plasmonic filter and a series-fed patch array, applied to an RTD working at 500 GHz to improve the overall radiation performance. The metallic array is designed through full-wave simulations, and the achieved results for both designs show a large reduction in the main lobe angle. The broadside directivity of the plasmonic filter and the series-fed patch array design reaches 5.4 dBi and 12.5 dBi, respectively.
{"title":"Improving the Radiation Performance of Resonant-Tunneling Diode by Using Planar Metallic Arrays","authors":"Mingxiang Stephen Li, S. Suzuki, C. Fumeaux, W. Withayachumnankul","doi":"10.1109/IRMMW-THz50926.2021.9567317","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567317","url":null,"abstract":"Resonant-tunneling diodes (RTDs) are promising candidates for terahertz sources but typically exhibit an unexpected large tilt angle in the main lobe of their radiation pattern. In this paper, we present two types of planar metallic arrays, a plasmonic filter and a series-fed patch array, applied to an RTD working at 500 GHz to improve the overall radiation performance. The metallic array is designed through full-wave simulations, and the achieved results for both designs show a large reduction in the main lobe angle. The broadside directivity of the plasmonic filter and the series-fed patch array design reaches 5.4 dBi and 12.5 dBi, respectively.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"8 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78923701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567467
K. Ikamas, D. But, A. Cesiul, C. Kołaciński, W. Knap, A. Lisauskas
A free space 252 GHz quasi-optical emitter-detector pair (optopair) is implemented in standard Si CMOS technology. The THz source consists of a voltage-controlled differential field-effect-transistor (FET) based Colpitts oscillator emitting at the third harmonic with total radiated power -11.1 dBm and 35 mW DC power consumption. The detector is a resonant-antenna-coupled FET-based power detector for quasi-optic coupling through the substrate lens. The detector exhibits a minimum optical noise equivalent power as low as $22{text{pW}}/sqrt {{text{Hz}}} $ at 252 GHz. The system reveals 61.7 dB power signal to noise for 1 Hz equivalent noise bandwidth in the direct detection regime. The practical application of the pair for two-dimensional imaging is also demonstrated.
{"title":"252-GHz Compact All-Electronic CMOS Optopair with SNR of 62 dB","authors":"K. Ikamas, D. But, A. Cesiul, C. Kołaciński, W. Knap, A. Lisauskas","doi":"10.1109/IRMMW-THz50926.2021.9567467","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567467","url":null,"abstract":"A free space 252 GHz quasi-optical emitter-detector pair (optopair) is implemented in standard Si CMOS technology. The THz source consists of a voltage-controlled differential field-effect-transistor (FET) based Colpitts oscillator emitting at the third harmonic with total radiated power -11.1 dBm and 35 mW DC power consumption. The detector is a resonant-antenna-coupled FET-based power detector for quasi-optic coupling through the substrate lens. The detector exhibits a minimum optical noise equivalent power as low as $22{text{pW}}/sqrt {{text{Hz}}} $ at 252 GHz. The system reveals 61.7 dB power signal to noise for 1 Hz equivalent noise bandwidth in the direct detection regime. The practical application of the pair for two-dimensional imaging is also demonstrated.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"17 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78433018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567587
Jin Meng, Haotian Zhu, Dehai Zhang, Hao Li, Yuh-Jing Li, Siyu Liu
Compared with Gallium Arsenide material, GaN device has better power endurance characteristics, and hence has great potential in the development of high power source. This paper proposes a heterojunction structure of GaN Schottky diode to improve the electron mobility of the device, and the cut-off frequency is over 250 GHz. Furthermore, a 120 GHz doubler is designed based on the proposed device. The simulated result shows that the conversion efficiency reaches 15% when the input power is 1 W.
{"title":"Design of a 120GHz Doubler based on AlGaN/GaN Schottky diode","authors":"Jin Meng, Haotian Zhu, Dehai Zhang, Hao Li, Yuh-Jing Li, Siyu Liu","doi":"10.1109/IRMMW-THz50926.2021.9567587","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567587","url":null,"abstract":"Compared with Gallium Arsenide material, GaN device has better power endurance characteristics, and hence has great potential in the development of high power source. This paper proposes a heterojunction structure of GaN Schottky diode to improve the electron mobility of the device, and the cut-off frequency is over 250 GHz. Furthermore, a 120 GHz doubler is designed based on the proposed device. The simulated result shows that the conversion efficiency reaches 15% when the input power is 1 W.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"3 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72650914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a ultrathin broadband and large incident angle metamaterial absorber by introducing a near-field coupling of split-ring resonators and the non-uniform periodic arrangement is proposed, which demonstrates intentional performance in terms of bandwidth and large-angle absorption. The results show that a bandwidth of absorption at 70% from 13 GHz to 34 GHz. Absorber has good stability for TE and TM modes at large incident angles and exhibits more than 80% absorptivity up to 60° incident angles for TM mode. This finding provide a novel technique for broadband device design, which could bring about a wide range of applications in microwave technology.
{"title":"Design of a Ultrathin Broadband and Large Incident Angle Metamaterial Absorber","authors":"Shuai Huang, Zewei Wu, Minxing Wang, Youlei Pu, Jianxun Wang, Yong Luo","doi":"10.1109/IRMMW-THz50926.2021.9567499","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567499","url":null,"abstract":"In this paper, a ultrathin broadband and large incident angle metamaterial absorber by introducing a near-field coupling of split-ring resonators and the non-uniform periodic arrangement is proposed, which demonstrates intentional performance in terms of bandwidth and large-angle absorption. The results show that a bandwidth of absorption at 70% from 13 GHz to 34 GHz. Absorber has good stability for TE and TM modes at large incident angles and exhibits more than 80% absorptivity up to 60° incident angles for TM mode. This finding provide a novel technique for broadband device design, which could bring about a wide range of applications in microwave technology.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"50 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76587836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567161
Shu Li, Shichao Li, Shougong Miao
A W Band coherent frequency synthesizer with frequency-agile, phase-regulated, low-spur and multiple-output is developed for FMCW radar. Measured results show that it has low-spur and low phase-noise performance.
{"title":"Development of W Band frequency synthesizer for coherent frequency agile Radar","authors":"Shu Li, Shichao Li, Shougong Miao","doi":"10.1109/IRMMW-THz50926.2021.9567161","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567161","url":null,"abstract":"A W Band coherent frequency synthesizer with frequency-agile, phase-regulated, low-spur and multiple-output is developed for FMCW radar. Measured results show that it has low-spur and low phase-noise performance.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"69 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77511261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-29DOI: 10.1109/IRMMW-THz50926.2021.9567458
Xing Xu, Yindong Huang, Ruixing Wang, Shiyou Wu, G. Fang
In this paper, we demonstrate a method to modulate the intensity and central frequency of THz generation from two-color laser-induced air plasmas, via transforming the pump Gaussian beams into vortex beams. Under the same input laser energy, the outputs of THz emission generated by the vortex beam can be enhanced, showing the potential of producing stronger THz radiation. Meanwhile, the vortex pump-beams also provide an unique possibility to modulate the central frequency of THz outputs, implying an all-optical method of THz modulation based on the shaped plasmas.
{"title":"Modulations of THz Wave from Vortex Beam Induced Air Plasmas","authors":"Xing Xu, Yindong Huang, Ruixing Wang, Shiyou Wu, G. Fang","doi":"10.1109/IRMMW-THz50926.2021.9567458","DOIUrl":"https://doi.org/10.1109/IRMMW-THz50926.2021.9567458","url":null,"abstract":"In this paper, we demonstrate a method to modulate the intensity and central frequency of THz generation from two-color laser-induced air plasmas, via transforming the pump Gaussian beams into vortex beams. Under the same input laser energy, the outputs of THz emission generated by the vortex beam can be enhanced, showing the potential of producing stronger THz radiation. Meanwhile, the vortex pump-beams also provide an unique possibility to modulate the central frequency of THz outputs, implying an all-optical method of THz modulation based on the shaped plasmas.","PeriodicalId":6852,"journal":{"name":"2021 46th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)","volume":"15 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2021-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77517968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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