Optical Materials Express最新文献

{"title":"Engineering electrically tunable TiN/SiO2 epsilon-near-zero metamaterials","authors":"Joseph Garbarino, John G. Jones, Peter R. Stevenson, Cynthia T. Bowers, Krishnamurthy Mahalingam, and Lyuba Kuznetsova","doi":"10.1364/ome.519794","DOIUrl":"https://doi.org/10.1364/ome.519794","url":null,"abstract":"Electrically tunable TiN/SiO₂/TiN epsilon-near-zero photonic structures with various parameters were fabricated using the reactive DC magnetron sputtering approach. Effective medium approximation was used to predict the optical permittivity of a multilayered TiN/SiO₂ metamaterial and guide the design/fabrication. Experimental reflectance measurements for tunable TiN/SiO₂/TiN structures were obtained using the ellipsometer technique in the visible and near-infrared spectral ranges. Results show that reflectance for biased (12 V) and un-biased bulk TiN/SiO₂/TiN structure changes up to ∼ 2% with the spectral shift at the ENZ spectral point ∼ 10 nm for samples with an optimal SiO₂ dielectric layer (thickness d=10 nm). Reflectance measurements for multilayered tunable TiN/SiO₂/TiN structures show strong variation in reflectance change for s- polarized light at epsilon-near-zero wavelengths due to applied voltage (12 V). We expect that the results of this research study of the tunable TiN/SiO₂/TiN epsilon-near-zero photonic structures will potentially be useful for the photonic density of states engineering, surface sensing, and metamaterial-based super-resolution imaging.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"2 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seedless synthesis of Au nanoplates with tunable plasmonic peaks","authors":"Yuhao Zheng, Min Li, and Deyuan Shen","doi":"10.1364/ome.522159","DOIUrl":"https://doi.org/10.1364/ome.522159","url":null,"abstract":"Au nanoplates with tunable in-plane dipolar localized surface plasmon resonance peaks in a broad range from the visible to near-infrared region were obtained in high yield using a seedless wet chemical growth method after purification. Cetyltrimethylammonium chloride was used as a surfactant, while hydrogen peroxide and sodium borohydride were used as the weak and strong reducing agents, respectively. The edge length and in-plane dipolar localized surface plasmon resonance peak of the Au nanoplates could be adjusted by varying the amounts of hydrogen peroxide and sodium borohydride. The Au nanoplates were further used as the saturable absorber to generate pulsed laser output in a passively Q-switched solid-state laser at approximately 2 µm. Our study offers a new method for obtaining Au nanoplates with tunable plasmonic peaks over a broad range.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"54 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the optical gain at 1550 nm of erbium-oxalate single crystals","authors":"R. E. López-Romero, G. G. Pérez-Sánchez, I. Aldaya, D. Y. Medina, E. L. Martínez-Piñeiro, I. A. Figueroa, and R. Escudero","doi":"10.1364/ome.515335","DOIUrl":"https://doi.org/10.1364/ome.515335","url":null,"abstract":"Erbium is well-recognized as a key element for optical amplification at the 1550 nm operation band. However, the limited solubility of this material in vitreous matrices sets a critical constraint to the achievable optical gain, which limits its applicability in photonic integrated platforms. One of the solutions to increase the concentration of erbium is to employ a crystalline structure instead of a glass. In this paper, we characterize samples of erbium and erbium-ytterbium oxalate single crystals synthesized using the gel diffusion method. X-ray diffraction spectra and thermogravimetric analyses reveal that the synthesis method indeed generated the expected compound, and the pump-and-probe experiments demonstrate an on-off gain coefficient of ≈ 6.5 dB/mm, making this material a high-potential candidate for the implementation of integrated optical amplifiers.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"88 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced photoelectron emission in a large area aluminum nanohole array via a deep-UV surface plasmon","authors":"Hirofumi Morisawa, Atsushi Ono, Koki Ikegami, Wataru Inami, and Yoshimasa Kawata","doi":"10.1364/ome.522182","DOIUrl":"https://doi.org/10.1364/ome.522182","url":null,"abstract":"We measured the photoelectron emission efficiency of aluminum (Al) nanohole arrays fabricated by colloidal lithography and demonstrated the enhancement of photoelectron emission in the deep-UV region via surface plasmon resonances. The Al nanohole arrays for increasing absorption in the deep-UV region were designed using the finite-difference time-domain method and used as photocathodes to enhance the photoelectron emission efficiency. The enhancement factor improved by up to 3.5 times for the optimized nanohole array. Using a two-dimensional mapping system, we demonstrated that the photoelectron emission depended on the uniformity of the sample and diameter of the nanohole arrays. Al nanohole arrays fabricated by colloidal lithography can be used to develop highly sensitive surface-detecting optical sensors and highly efficient surface-emitting electron sources. The two-dimensional mapping system can facilitate the development of highly efficient photocathodes.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"45 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140573018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fast-switching reconfigurable metadevice with metasurface-induced liquid crystal alignment for light modulator applications","authors":"Xin Chang, Mike Pivnenko, Angadjit Singh, Weijie Wu, Pawan Shrestha, and Daping Chu","doi":"10.1364/ome.520326","DOIUrl":"https://doi.org/10.1364/ome.520326","url":null,"abstract":"Metasurface technology is progressing rapidly towards commercialization and productization, due to its unparallelled advantages over conventional optical solutions. The reconfigurable metasurface, exhibiting more flexibility and capacity than its static counterpart, has been one of the most pursued features of metasurface. In this work, we present liquid crystal-based dynamic metasurface by immersing metasurface in nematic liquid crystal environment. No alignment material was used, and liquid crystal was aligned directly by metasurface. The alignment quality was characterized and the intensity contrast of 33 was obtained. Optical amplitude modulation was achieved with the modulation depth of 91% at the wavelength of 1375 nm. Moreover, sub-micrometre cell gap of 875 nm was realized, and the response time was measured to be sub-millisecond at room temperature, translating to > 1KHz operation frequency. The higher operation frequency of > 3.4 KHz was recorded at elevated temperature. The key performance indicators demonstrated in this work showcase the promising future of liquid crystal – based reconfigurable metasurface, especially for fast light modulator applications.//Metasurface technology is progressing rapidly toward commercialization and productization due to its unparalleled advantages over conventional optical solutions. The reconfigurable metasurface, exhibiting more flexibility and capacity than its static counterpart, has been one of the most pursued features of the metasurface. In this work, we present a liquid crystal-based dynamic metasurface by immersing the metasurface in a nematic liquid crystal environment. No alignment material was used, and liquid crystal was aligned directly by metasurface. The alignment quality was characterized, and the intensity contrast of 33 was obtained. Optical amplitude modulation was achieved with a modulation depth of 91% at the wavelength of 1375 nm. Moreover, a sub-micrometer cell gap of 875 nm was realized, and the response time was measured to be sub-millisecond at room temperature, translating to > 1KHz operation frequency. The higher operation frequency of > 3.4 KHz was recorded at elevated temperatures. The key performance indicators demonstrated in this work showcase the promising future of liquid crystal-based reconfigurable metasurface, especially for fast light modulator applications.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"34 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal cascading of dielectric waveguides [Invited]","authors":"Victor Pacheco-Peña and Nader Engheta","doi":"10.1364/ome.516262","DOIUrl":"https://doi.org/10.1364/ome.516262","url":null,"abstract":"Photonic time interfaces, as the temporal analogue of spatial interfaces between two media, consist of a rapid change of the electromagnetic properties of a material (such as permittivity, <i>ε</i>, and permeability, <i>μ</i>) while the wave is present in the material. Here we exploit cascading of such time interfaces in spatially cascaded guided-wave structures such as slab waveguides and ring resonators by considering that the relative permittivity of the cladding of dielectric waveguides is rapidly changed at different moments of time from <i>ε_{clad_1}</i> to <i>ε_{clad_2}</i>, while the material of the core remains unchanged in time. It is shown how such time-dependent cladding can enable frequency conversion within the space-time dielectric ring resonator and slab waveguides due to an induced modification of the effective refractive index of the mode propagating within such photonic device. Cascaded frequency conversion is achieved in such cascaded space-time dielectric waveguides and ring resonators, showing how the combination of space and time interfaces can offer further opportunities for manipulation of light-matter interaction using four-dimensional (4D) photonic structures.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"34 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localization landscape of optical waves in multifractal photonic membranes","authors":"Tornike Shubitidze, Yilin Zhu, Hari Sundar, and Luca Dal Negro","doi":"10.1364/ome.520201","DOIUrl":"https://doi.org/10.1364/ome.520201","url":null,"abstract":"In this paper, we investigate the localization properties of optical waves in disordered systems with multifractal scattering potentials. In particular, we apply the localization landscape theory to the classical Helmholtz operator and, without solving the associated eigenproblem, show accurate predictions of localized eigenmodes for one- and two-dimensional multifractal structures. Finally, we design and fabricate nanoperforated photonic membranes in silicon nitride (SiN) and image directly their multifractal modes using leaky-mode spectroscopy in the visible spectral range. The measured data demonstrate optical resonances with multiscale intensity fluctuations in good qualitative agreement with numerical simulations. The proposed approach provides a convenient strategy to design multifractal photonic membranes, enabling rapid exploration of extended scattering structures with tailored disorder for enhanced light-matter interactions.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"347 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passively harmonic mode-locked erbium-doped fiber laser with a gold nanofilm saturable absorber","authors":"Changjian Lv, Fanchao Meng, Tianqi Zhang, Junjie Wang, Qi Yan, Zhixu Jia, Weiping Qin, and Guanshi Qin","doi":"10.1364/ome.521096","DOIUrl":"https://doi.org/10.1364/ome.521096","url":null,"abstract":"We demonstrate a 1.5 GHz harmonic mode-locked erbium-doped fiber laser by incorporating gold nanofilm as a saturable absorber (SA). The high-quality gold nanofilm SA fabricated by the physical vapor deposition method possesses a high modulation depth of 12.9% and a low saturation intensity of 1.69 MW/cm² at 1.56 µm, facilitating the generation of harmonic mode-locking. The fundamental mode-locked operation was obtained at 1564.7 nm, with a pulse duration of 586 fs and a repetition rate of 34.235 MHz. At the pump power of 610 mW, 44th-order harmonic mode-locking with a repetition rate of 1.506 GHz was achieved, which is the highest yet reported in mode-locked fiber lasers using gold nanomaterials as SAs. Moreover, the gold nanofilm-based harmonic mode-locked fiber laser shows relatively high signal-to-noise ratios, high output power, and good stability. These results highlight the advantage of the gold nanofilm-based SA in realizing high repetition rate laser sources.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"26 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140168710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface wave control via unidirectional surface magnetoplasmon waveguide arrays","authors":"Shiqing Li, Weipu Tu, Hang Zhang, Jinhua Yan, and Linfang Shen","doi":"10.1364/ome.518730","DOIUrl":"https://doi.org/10.1364/ome.518730","url":null,"abstract":"Freely tailoring the wavefronts of surface waves (SWs), including surface plasmon polaritons (SPPs) and their equivalent counterparts, holds significant importance in the field of on-chip photonics. However, conventional diffraction-optics based devices often suffer from limited functionalities and low working efficiencies. Here, we present a novel concept of a unidirectional surface magnetoplasmon (USMP) waveguide array composed of carefully engineered subwavelength-spaced unidirectional waveguide slits. By utilizing the unique propagation properties of USMPs within these waveguides, the USMP waveguide array efficiently converts USMPs into SWs with predetermined wavefronts. As proof of the concept, we numerically demonstrate this new principle through the design of two microwave USMP waveguide arrays using a metal-air-YIG structure, which directly converts USMPs into SWs with the wavefronts of Bessel beam and focusing. Additionally, we extend this concept to the terahertz regime and achieve beam deflection of SWs using a metal-air-semiconductor waveguide array. These findings may inspire the development of highly miniaturized on-chip devices for integrated photonics applications.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"203 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-shell diamond-graphene needles with silicon-vacancy color centers","authors":"Mariam Maku Quarshie, Sergei Malykhin, and Polina Kuzhir","doi":"10.1364/ome.518724","DOIUrl":"https://doi.org/10.1364/ome.518724","url":null,"abstract":"Color centers in diamond nanostructures open new horizons in biomedicine, offering a biocompatible material platform for sensing temperature, pH, and magnetic field. Covering of the color centers enriched diamonds with graphene shell can essentially extend their application potential. Specifically, under irradiation with ultrashort laser pulses, the highly absorptive graphene shell can be used for excitation of a shock acoustic wave which can be used for cancer cell destruction or drug photoactivation through the Joule heating. In this study, we present a novel method for creating diamond-graphite core-shell structures. Through precise control of the growth of the graphitic layer on Single Crystal Diamond Needles (SCDNs) via vacuum annealing at 900°C for 30 minutes, we preserved 57% of the light emission from silicon-vacancy (SiV^-) centers while maintaining their spectral peaks. Contrary to our expectations of reduced SiV^- luminescence due to the presence of the graphitic shell, we observed that the initial high brightness of SiV^- in the diamond needles persisted. This enabled us to detect SiV^- luminescence spectrally, even within the core-shell structures. Our results underscore the tunability of these structures’ properties through temperature and duration control, suggesting promising prospects for their application in advanced biomedical tools with sensing capabilities.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"73 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}