Morphological disorder is commonplace in bioworld structures, as exemplified by the layered helical structures in the exocuticle in many beetle species. Circular-polarization-state selective reflection from disordered chiral structures was theoretically explored, the disorder being that each helical turn may be different from its adjacent helical turns. The boundary-value problem of plane-wave reflection by a disordered chiral structure was solved. Numerical results indicate the remarkable resilience of circular-polarization-state-selective reflection against morphological disorder.
{"title":"Resilience of circular-polarization-state-sensitive reflection against morphological disorder in chiral structures","authors":"Akhlesh Lakhtakia","doi":"10.1117/1.jnp.18.036005","DOIUrl":"https://doi.org/10.1117/1.jnp.18.036005","url":null,"abstract":"Morphological disorder is commonplace in bioworld structures, as exemplified by the layered helical structures in the exocuticle in many beetle species. Circular-polarization-state selective reflection from disordered chiral structures was theoretically explored, the disorder being that each helical turn may be different from its adjacent helical turns. The boundary-value problem of plane-wave reflection by a disordered chiral structure was solved. Numerical results indicate the remarkable resilience of circular-polarization-state-selective reflection against morphological disorder.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"62 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141773068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stacked submonolayer (SML) InAs/GaAs nanostructures, assembled by cyclic, alternating deposition of SML (<1 ML) InAs and few-monolayer GaAs using molecular beam epitaxy, have been attracting interest, owing to their unique optical and electronic properties. Recently, it has been demonstrated that a growth transition during SML deposition can lead to two types of nanostructures: 2D islands and 3D structures. The properties of SML nanostructures also make them strong candidates for spintronic and quantum information applications. However, the spin properties of SML nanostructures have not yet been investigated. In this study, the spin properties of SML nanostructures are investigated using optical spin injection and detection experiments by circularly polarized photoluminescence (CP-PL). Spins are injected into the SML nanostructures using the optical selection rules in GaAs for CP excitation, whereas the spin state in the SML nanostructures is detected by measuring the right (σ+) and left (σ−) CP intensity components of the PL. The degree of CP-PL is estimated by quantity P=[I(σ+)−I(σ−)]/[I(σ+)+I(σ−)], where I(σ±) is the luminescence intensity for the σ± component. The quantity P is a direct measure of the spin state in the SML nanostructures. Using a sample containing both 2D and 3D SML nanostructures, experimental results yield a relatively high P=6% for the 3D SML nanostructures and a relatively low P=2% for the 2D SML nanostructures. The difference may be attributed to the higher carrier confinement for 3D SML resulting in preservation of the spin state. Analytical calculations considering the spin and carrier lifetimes are also carried out to model the experimental results. These results provide insight into the fundamental spin dynamics of 2D and 3D SML nanostructures and pave the way for spintronics and quantum information applications of SML nanostructures.
{"title":"Optical spin injection and detection in submonolayer InAs/GaAs nanostructures by circularly polarized photoluminescence","authors":"Ronel Christian I. Roca, Itaru Kamiya","doi":"10.1117/1.jnp.18.036001","DOIUrl":"https://doi.org/10.1117/1.jnp.18.036001","url":null,"abstract":"Stacked submonolayer (SML) InAs/GaAs nanostructures, assembled by cyclic, alternating deposition of SML (<1 ML) InAs and few-monolayer GaAs using molecular beam epitaxy, have been attracting interest, owing to their unique optical and electronic properties. Recently, it has been demonstrated that a growth transition during SML deposition can lead to two types of nanostructures: 2D islands and 3D structures. The properties of SML nanostructures also make them strong candidates for spintronic and quantum information applications. However, the spin properties of SML nanostructures have not yet been investigated. In this study, the spin properties of SML nanostructures are investigated using optical spin injection and detection experiments by circularly polarized photoluminescence (CP-PL). Spins are injected into the SML nanostructures using the optical selection rules in GaAs for CP excitation, whereas the spin state in the SML nanostructures is detected by measuring the right (σ+) and left (σ−) CP intensity components of the PL. The degree of CP-PL is estimated by quantity P=[I(σ+)−I(σ−)]/[I(σ+)+I(σ−)], where I(σ±) is the luminescence intensity for the σ± component. The quantity P is a direct measure of the spin state in the SML nanostructures. Using a sample containing both 2D and 3D SML nanostructures, experimental results yield a relatively high P=6% for the 3D SML nanostructures and a relatively low P=2% for the 2D SML nanostructures. The difference may be attributed to the higher carrier confinement for 3D SML resulting in preservation of the spin state. Analytical calculations considering the spin and carrier lifetimes are also carried out to model the experimental results. These results provide insight into the fundamental spin dynamics of 2D and 3D SML nanostructures and pave the way for spintronics and quantum information applications of SML nanostructures.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"6 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141568754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We studied spectroscopical properties of tiny TiO2 nanoparticles (TiO2 NPs) with potential applications by the stimulation of multi-modal energy modes. Thus, nanoparticles of 2 to 4 nm sizes were modified with short modified organosilane with a fluorescent laser dye reporter. By this manner, it was covered with silanized spacer lengths of few nm with an additional protective shell. The non-modified TiO2 NPs showed high interactions between them due to their reduced sizes that afforded to homogeneous nano-patterned arrays observed by TEM. Silanized nanoparticles also afforded higher dispersible colloidal dispersion with strong interactions. As it is known, silanol groups could form strong polar and hydrogen bridges between them, but the aggregates could be easily re-dispersed just by sonication. By this manner, generation of a high-ordered nano-pattern was lost in the absence of silica shells. By dynamic light scattering, I recorded within colloidal dispersions sizes of 2 to 3 nm in presence of aqueous solvent and smaller nanoaggregates of 30 nm corresponding to decamer forms. In this context, I highlighted the possibility of managing interactions and nano-patterns controlling nano-surfaces and media. Non-labeled TiO2 NPs showed strong absorptions centered at 298.0 and 560.0 nm. Moreover, modified nanoparticles showed a constant and proportional increase of the 298.0 nm absorption band with the augmentation of the concentration. Moreover, the UV band was accompanied with a redshifted maximal absorption wavelength by the fluorophore incorporated from 553.0 to 557.0 nm. This fact was explained between an interaction between the absorption of the laser dye centered at 537 nm and the longer band by the nanoplatforms. Then, in order to evaluate their interactions in the excited state, I evaluated fluorescence lifetime decays (τ) of the free fluorophore and deposed on nanoplatforms. In addition, I evaluated the detection of the modified TiO2 nanoplatforms within in-flow cytometry (IFC). In this manner, I observed τ shortening accompanied with augmented counting of fluorescence events detected. It should be noted that in these conditions, I did not observe degradation of the fluorescent reporter. However, in absence of the modified organosilanes, I observed potential insights of fast photo-degradation under UV light irradiation. Therefore, I designed and synthesized a stable and improved tiny nano-emitter with potential use for nanophotonics, biophotonics, and nanomedicine applications. Thus, in this perspective, I discuss the development of multimodal nanoplatforms for varied functionalities and applications.
{"title":"Tiny hybrid modified organosilane-titanium dioxide nanocomposites with dual photonic behavior: insights for enhanced in-flow signaling","authors":"Angel Guillermo Bracamonte","doi":"10.1117/1.jnp.18.036004","DOIUrl":"https://doi.org/10.1117/1.jnp.18.036004","url":null,"abstract":"We studied spectroscopical properties of tiny TiO2 nanoparticles (TiO2 NPs) with potential applications by the stimulation of multi-modal energy modes. Thus, nanoparticles of 2 to 4 nm sizes were modified with short modified organosilane with a fluorescent laser dye reporter. By this manner, it was covered with silanized spacer lengths of few nm with an additional protective shell. The non-modified TiO2 NPs showed high interactions between them due to their reduced sizes that afforded to homogeneous nano-patterned arrays observed by TEM. Silanized nanoparticles also afforded higher dispersible colloidal dispersion with strong interactions. As it is known, silanol groups could form strong polar and hydrogen bridges between them, but the aggregates could be easily re-dispersed just by sonication. By this manner, generation of a high-ordered nano-pattern was lost in the absence of silica shells. By dynamic light scattering, I recorded within colloidal dispersions sizes of 2 to 3 nm in presence of aqueous solvent and smaller nanoaggregates of 30 nm corresponding to decamer forms. In this context, I highlighted the possibility of managing interactions and nano-patterns controlling nano-surfaces and media. Non-labeled TiO2 NPs showed strong absorptions centered at 298.0 and 560.0 nm. Moreover, modified nanoparticles showed a constant and proportional increase of the 298.0 nm absorption band with the augmentation of the concentration. Moreover, the UV band was accompanied with a redshifted maximal absorption wavelength by the fluorophore incorporated from 553.0 to 557.0 nm. This fact was explained between an interaction between the absorption of the laser dye centered at 537 nm and the longer band by the nanoplatforms. Then, in order to evaluate their interactions in the excited state, I evaluated fluorescence lifetime decays (τ) of the free fluorophore and deposed on nanoplatforms. In addition, I evaluated the detection of the modified TiO2 nanoplatforms within in-flow cytometry (IFC). In this manner, I observed τ shortening accompanied with augmented counting of fluorescence events detected. It should be noted that in these conditions, I did not observe degradation of the fluorescent reporter. However, in absence of the modified organosilanes, I observed potential insights of fast photo-degradation under UV light irradiation. Therefore, I designed and synthesized a stable and improved tiny nano-emitter with potential use for nanophotonics, biophotonics, and nanomedicine applications. Thus, in this perspective, I discuss the development of multimodal nanoplatforms for varied functionalities and applications.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"18 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141773069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface-enhanced Raman spectroscopy (SERS) performed in microfluidic channels offers multiple benefits to the sensitive and reliable detection of dilute analytes while utilizing the advantages of microfluidics, including small samples, high throughput, and portability. Physical deposition of metallic nanoparticles by techniques, such as electron beam deposition, results in dense populations of nanoparticles and hotspots between nanoparticles for sensitive detection. However, not only do physically deposited SERS-active surfaces necessitate additional steps during device fabrication, but also surface fabrication is itself complicated by the constraints imposed by the microfluidic channel. Our work demonstrates a robust approach to the physical fabrication of an SERS-active substrates inside a poly(dimethylsiloxane) (PDMS) microfluidic channel. Direct growth of zinc oxide nanowires inside the PDMS channel and e-beam deposition of silver to coat the nanowires was performed before bonding PDMS to glass. This process enables label-free SERS sensing of micromolar crystal violet and melamine with minimal spectral interference from the PDMS-based channel.
{"title":"Fabrication of silver-decorated zinc oxide nanowire sensor in microchannels for surface-enhanced Raman spectroscopy","authors":"Andrew L. Cook, Todd D. Giorgio","doi":"10.1117/1.jnp.18.036002","DOIUrl":"https://doi.org/10.1117/1.jnp.18.036002","url":null,"abstract":"Surface-enhanced Raman spectroscopy (SERS) performed in microfluidic channels offers multiple benefits to the sensitive and reliable detection of dilute analytes while utilizing the advantages of microfluidics, including small samples, high throughput, and portability. Physical deposition of metallic nanoparticles by techniques, such as electron beam deposition, results in dense populations of nanoparticles and hotspots between nanoparticles for sensitive detection. However, not only do physically deposited SERS-active surfaces necessitate additional steps during device fabrication, but also surface fabrication is itself complicated by the constraints imposed by the microfluidic channel. Our work demonstrates a robust approach to the physical fabrication of an SERS-active substrates inside a poly(dimethylsiloxane) (PDMS) microfluidic channel. Direct growth of zinc oxide nanowires inside the PDMS channel and e-beam deposition of silver to coat the nanowires was performed before bonding PDMS to glass. This process enables label-free SERS sensing of micromolar crystal violet and melamine with minimal spectral interference from the PDMS-based channel.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"47 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plasmonic supercrystals (PSCs) made by colloidal self-assembly metallic nanoparticles can be regarded as a special kind of optical metamaterials with intriguing properties, such as engineered refractive indices and densely distributed near field “hot spots.” Analysis of the Purcell effect of PSCs is crucial for many applications related to light-emission processes, such as surface-enhanced Raman scattering and spontaneous emission enhancement. We present a detailed theoretical and numerical study on the Purcell effect of films and nanocavities made of PSCs. We first demonstrate that the spectral response of the Purcell effect of a monolayer PSC can be basically divided into the surface plasmon polariton regime, the collective plasmon (CP) regime, and the dielectric regime. In particular, we reveal that the resonances in the CP regime have rich fine structures of near fields, resulting in a strong dependence of the Purcell effect on the position and polarization of emitters. We further show that nanocavities consist of PSCs that sustain Mie-like electric and magnetic multipolar resonances that can be utilized to enhance the Purcell effect in the near-infrared band. Our results are helpful for understanding the light–matter interactions at nanoscale and may promote applications of PSCs in light-emission engineering.
{"title":"Analysis of the Purcell effect of plasmonic supercrystal films and nanocavities made by close-packed metallic nanoparticles","authors":"Zejun Duan, Zenghao Zhao, Peixiang Li, Xiaoming Zhang, Qiang Zhang","doi":"10.1117/1.jnp.18.036003","DOIUrl":"https://doi.org/10.1117/1.jnp.18.036003","url":null,"abstract":"Plasmonic supercrystals (PSCs) made by colloidal self-assembly metallic nanoparticles can be regarded as a special kind of optical metamaterials with intriguing properties, such as engineered refractive indices and densely distributed near field “hot spots.” Analysis of the Purcell effect of PSCs is crucial for many applications related to light-emission processes, such as surface-enhanced Raman scattering and spontaneous emission enhancement. We present a detailed theoretical and numerical study on the Purcell effect of films and nanocavities made of PSCs. We first demonstrate that the spectral response of the Purcell effect of a monolayer PSC can be basically divided into the surface plasmon polariton regime, the collective plasmon (CP) regime, and the dielectric regime. In particular, we reveal that the resonances in the CP regime have rich fine structures of near fields, resulting in a strong dependence of the Purcell effect on the position and polarization of emitters. We further show that nanocavities consist of PSCs that sustain Mie-like electric and magnetic multipolar resonances that can be utilized to enhance the Purcell effect in the near-infrared band. Our results are helpful for understanding the light–matter interactions at nanoscale and may promote applications of PSCs in light-emission engineering.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"63 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work proposes a mask design method to change the film thickness distribution for the rotary plane coating machine, and successfully deposits a continuously variable filter. The results indicate that the test spectrum exhibits linear gradient passband filtering characteristics at different positions along the spatial direction. The continuously variable filter operates between 650 and 1050 nm, with the linear dispersion coefficient of 32.92 nm/mm over 12 mm. The peak transmittance of the filter is more than 80%, the transmittance of cutoff band is less than 0.1%, and the half bandwidth of the passband is almost consistent with 1.5% of the central wavelength. These parameter indicators fully meet the design requirements.
{"title":"Design of mask for depositing continuously variable filter","authors":"Xiaodan Gao, Chun Wei","doi":"10.1117/1.jnp.18.026008","DOIUrl":"https://doi.org/10.1117/1.jnp.18.026008","url":null,"abstract":"This work proposes a mask design method to change the film thickness distribution for the rotary plane coating machine, and successfully deposits a continuously variable filter. The results indicate that the test spectrum exhibits linear gradient passband filtering characteristics at different positions along the spatial direction. The continuously variable filter operates between 650 and 1050 nm, with the linear dispersion coefficient of 32.92 nm/mm over 12 mm. The peak transmittance of the filter is more than 80%, the transmittance of cutoff band is less than 0.1%, and the half bandwidth of the passband is almost consistent with 1.5% of the central wavelength. These parameter indicators fully meet the design requirements.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"26 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We demonstrate the fabrication of an optical nanofiber tip (ONFT) using a two-step chemical etching technique. This technique employs 30% and 24% hydrofluoric (HF) acid for the first and second steps, respectively. In the first step, a silica single-mode fiber with a clad diameter of 125 μm and a core diameter of 9 μm is immersed in the HF acid for 90 min. The resultant fiber diameter is reduced to ∼45 μm. In the second step, the fiber is again immersed in the HF acid for 60–80 min. The etching time is controlled to achieve the desired tip diameter of the ONFT. We characterize fabricated ONFTs by measuring the optical transmission and surface morphology. The observed optical transmissions are more than 30%, and the tip diameters are less than 500 nm. The measured results readily reveal the merit of the employed technique as it is easy and cost effective. Due to the strong confinement of the electromagnetic field at the tip of ONFTs, these structures have versatile platforms with potential applications in sensing, photonics, and quantum optics.
{"title":"Fabrication and characterization of optical nanofiber tips","authors":"Resmi M, Elaganuru Bashaiah, Ramachandrarao Yalla","doi":"10.1117/1.jnp.18.026007","DOIUrl":"https://doi.org/10.1117/1.jnp.18.026007","url":null,"abstract":"We demonstrate the fabrication of an optical nanofiber tip (ONFT) using a two-step chemical etching technique. This technique employs 30% and 24% hydrofluoric (HF) acid for the first and second steps, respectively. In the first step, a silica single-mode fiber with a clad diameter of 125 μm and a core diameter of 9 μm is immersed in the HF acid for 90 min. The resultant fiber diameter is reduced to ∼45 μm. In the second step, the fiber is again immersed in the HF acid for 60–80 min. The etching time is controlled to achieve the desired tip diameter of the ONFT. We characterize fabricated ONFTs by measuring the optical transmission and surface morphology. The observed optical transmissions are more than 30%, and the tip diameters are less than 500 nm. The measured results readily reveal the merit of the employed technique as it is easy and cost effective. Due to the strong confinement of the electromagnetic field at the tip of ONFTs, these structures have versatile platforms with potential applications in sensing, photonics, and quantum optics.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"6 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jassim M. Jassim, Majid F. Haddawi, Hristo Kisov, Seyedeh M. Hamidi
A compacted random laser with a triple optical cavity is designed by directly coupling the compound between three cavities: the fundamental, ring, and external cavities. The laser action in this counterintuitive cavity is enabled by feedback from strong reflections on the inner and external surfaces, as well as scattering centers silver nanowires. This unique property of the triple optical cavity results in a lower laser threshold and enhanced emission spectra. These results provide up new possibilities for designing devices integrated and miniature technology.
{"title":"Plasmonic triple compound cavity random lasing: fabrication and characterization","authors":"Jassim M. Jassim, Majid F. Haddawi, Hristo Kisov, Seyedeh M. Hamidi","doi":"10.1117/1.jnp.18.026006","DOIUrl":"https://doi.org/10.1117/1.jnp.18.026006","url":null,"abstract":"A compacted random laser with a triple optical cavity is designed by directly coupling the compound between three cavities: the fundamental, ring, and external cavities. The laser action in this counterintuitive cavity is enabled by feedback from strong reflections on the inner and external surfaces, as well as scattering centers silver nanowires. This unique property of the triple optical cavity results in a lower laser threshold and enhanced emission spectra. These results provide up new possibilities for designing devices integrated and miniature technology.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the limited study, this work engineers the parameters controlling the rate of absorbed energy from a double quantum dot (DQD)-metal nanoparticle (MNP) system at plasmonic electromagnetically induced transparency (PEIT) considering the strong coupling between DQD and MNP. The modeling is of the material property for which the energy states and transition momenta are calculated. The analysis considers the orthogonalized plane wave between the wetting layer (WL)-QD transitions. A huge (10−5 W) total absorption rate (Qtotal) from the system is attained. This result is higher by four orders and the power applied is less by three orders than that obtained in the literature. Many features are studied. Neglecting the WL, the system spectrum is similar to the left-handed picture of the system with WL. The value of Q depends on the situation of the QD energy states through the variation of the QD size, MNP radius, and distance separating the system. In the DQD-MNP hybrid system, the controlling factor that gives a high Qtotal in the PEIT case is the DQD combination with a weak probe and enough pump, i.e., the DQD structure works as a whole structure, not as two QDs working separately. Such a structure allows for manipulating the flexibility of carriers between DQD states that are not found in other structures. From the results, one can conclude that DQD behavior under the pump, probe, and single tunneling component produces two transparent windows. Adding a second tunneling component creates four transparency windows depending on the values of these applied parameters.
{"title":"Engineering of plasmonic electromagnetically induced transparency from double quantum dot-metal nanoparticle structure","authors":"Asaad H. Hameed, Amin H. Al-Khursan","doi":"10.1117/1.jnp.18.026003","DOIUrl":"https://doi.org/10.1117/1.jnp.18.026003","url":null,"abstract":"Due to the limited study, this work engineers the parameters controlling the rate of absorbed energy from a double quantum dot (DQD)-metal nanoparticle (MNP) system at plasmonic electromagnetically induced transparency (PEIT) considering the strong coupling between DQD and MNP. The modeling is of the material property for which the energy states and transition momenta are calculated. The analysis considers the orthogonalized plane wave between the wetting layer (WL)-QD transitions. A huge (10−5 W) total absorption rate (Qtotal) from the system is attained. This result is higher by four orders and the power applied is less by three orders than that obtained in the literature. Many features are studied. Neglecting the WL, the system spectrum is similar to the left-handed picture of the system with WL. The value of Q depends on the situation of the QD energy states through the variation of the QD size, MNP radius, and distance separating the system. In the DQD-MNP hybrid system, the controlling factor that gives a high Qtotal in the PEIT case is the DQD combination with a weak probe and enough pump, i.e., the DQD structure works as a whole structure, not as two QDs working separately. Such a structure allows for manipulating the flexibility of carriers between DQD states that are not found in other structures. From the results, one can conclude that DQD behavior under the pump, probe, and single tunneling component produces two transparent windows. Adding a second tunneling component creates four transparency windows depending on the values of these applied parameters.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"28 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140884535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Omekulsum Damavandi Asli, Mohammad Yazdi, Behrad Rezaee Rezvan
We introduced a tunable terahertz broadband absorber with near-unity absorption based on a graphene metamaterial. A periodic array of star-shaped ring graphene resonators along with a silicon dioxide substrate backed with a ground plane forms the absorbing structure. The absorption rate of the ultimate optimal absorber is more than 90% in the 0.8 to 2.4 terahertz frequency range, which is equivalent to a relative bandwidth of 100% at a central frequency of 1.6 terahertz. It is shown that the proposed structure retains its absorption bandwidth with an absorption level of more than 75% up to a 60-deg elevation angle for different wave polarizations. In addition, by increasing the chemical potential of graphene in the proposed structure from 0.1 to 0.9 eV, the absorption rate of the structure can be tuned from 40% to nearly 100%. The effects of different geometrical parameters of the structure on the absorption rate of the structure are also investigated, and the absorption mechanism of the presented absorber is investigated by interference and impedance matching theories. Finally, the simulation results are compared with calculated analytical ones, where good agreement between the results is observed. The proposed absorber has potential application in terahertz frequencies such as cloaking, modulators, tunable filters, sensors, and imaging systems.
{"title":"Tunable broadband terahertz absorber based on star-shaped ring graphene metasurface","authors":"Omekulsum Damavandi Asli, Mohammad Yazdi, Behrad Rezaee Rezvan","doi":"10.1117/1.jnp.18.026004","DOIUrl":"https://doi.org/10.1117/1.jnp.18.026004","url":null,"abstract":"We introduced a tunable terahertz broadband absorber with near-unity absorption based on a graphene metamaterial. A periodic array of star-shaped ring graphene resonators along with a silicon dioxide substrate backed with a ground plane forms the absorbing structure. The absorption rate of the ultimate optimal absorber is more than 90% in the 0.8 to 2.4 terahertz frequency range, which is equivalent to a relative bandwidth of 100% at a central frequency of 1.6 terahertz. It is shown that the proposed structure retains its absorption bandwidth with an absorption level of more than 75% up to a 60-deg elevation angle for different wave polarizations. In addition, by increasing the chemical potential of graphene in the proposed structure from 0.1 to 0.9 eV, the absorption rate of the structure can be tuned from 40% to nearly 100%. The effects of different geometrical parameters of the structure on the absorption rate of the structure are also investigated, and the absorption mechanism of the presented absorber is investigated by interference and impedance matching theories. Finally, the simulation results are compared with calculated analytical ones, where good agreement between the results is observed. The proposed absorber has potential application in terahertz frequencies such as cloaking, modulators, tunable filters, sensors, and imaging systems.","PeriodicalId":16449,"journal":{"name":"Journal of Nanophotonics","volume":"23 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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