{"title":"Miniaturized refractive index sensor based on bound states in the continuum combined with lateral confinement","authors":"Yun Qiu, Xin Zhang, Kangni Wang, Linyong Qian","doi":"10.1016/j.optcom.2024.131265","DOIUrl":"10.1016/j.optcom.2024.131265","url":null,"abstract":"<div><div>Optical refractive index sensors with small footprints are essential components in compact biomedical and chemical analysis, owing to their unique advantages in size and real-time detection. In this work, we propose a miniaturized refractive index sensor based on bound states in the continuum (BICs) by utilizing compound gratings combined with two silver (Ag) mirrors on both sides. By confining light within the central grating region through reflection of the two Ag mirrors, we achieve a sensitivity of 362.07 nm/RIU and a figure of merit (FOM) of 1956.18 RIU<sup>−1</sup>, while maintaining a small horizontal dimension of 20.96 μm. Additionally, BIC occurs when the grating height is tuned within the range of 771 nm–803 nm, resulting in a narrow linewidth that can be utilized to achieve an enhanced FOM of 8726.22 RIU<sup>−1</sup>. Our research provides valuable insights for the development of high-performance on-chip sensors with compact footprints for future applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131265"},"PeriodicalIF":2.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Kaiyu Chai, Bo Hu, Zheng Fu, Yukang Li, Kaili Ren, Dongdong Han, Lipeng Zhu, Lei Liang, Yipeng Zheng
{"title":"Tunable diode laser absorption spectroscopy for gas detection with a negative curvature anti-resonant hollow-core fiber","authors":"Kaiyu Chai, Bo Hu, Zheng Fu, Yukang Li, Kaili Ren, Dongdong Han, Lipeng Zhu, Lei Liang, Yipeng Zheng","doi":"10.1016/j.optcom.2024.131278","DOIUrl":"10.1016/j.optcom.2024.131278","url":null,"abstract":"<div><div>In this study, an all-fiber gas sensing technology was proposed, which is based on tunable diode laser absorption spectroscopy in the near infrared. A negative curvature anti-resonant hollow-core fiber was used as the gas chamber and optical channel, and an opto-gas coupling miniature tee was used in the configuration. Down to ppb (parts-per-billion) level noise-equivalent concentration was achieved with a fast-response capability of less than 6 s. The results demonstrated strong long-term stability, with a relative standard deviation of approximately 2.1% over a 12-h period. This approach demonstrates a simple, robust, fast response and compact sensor configuration that contributes to better management of greenhouse gas emissions and environmental pollution.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131278"},"PeriodicalIF":2.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
{"title":"All-dielectric transmissive narrow-band filters adjustable within wide spectral range","authors":"Guangming Xiang, Yu Zhang, Xinmiao Lu, Lei Xiong, Zhaohui Zhang, Youfen Yuan","doi":"10.1016/j.optcom.2024.131280","DOIUrl":"10.1016/j.optcom.2024.131280","url":null,"abstract":"<div><div>The challenge of obtaining transmission spectra with both a wider tunable spectral range and high resolution persists. In this paper, a novel all-dielectric transmissive grating structure based on Mie resonance is proposed. The structure excites the Mie resonance by embedding a high refractive index contrast grating in a KF-Si film system band-stop filter. The dipole resonance energy is confined within the high refractive index silicon grating material, expanding the cutoff bandwidth of the KF-Si film system to over 400 nm and achieving single-peak transmission in the visible range. And the continuous transmission spectrum has an adjustable range of 300 nm with the highest spectral resolution (FWHM) (∼20 nm) can be achieved by adjusting the grating period. To suppress the coupling energy excitation between the higher-order magnetic dipole and the substrate, a silicon-rich nitride (SRN) matching layer is introduced between the KF-Si film system and the substrate. This layer enhances the intensity of the resonance peaks while simultaneously suppressing the short-wavelength sidebands, thereby improving the saturation and purity of the spectrum. In addition, we obtained a large angular tolerance of up to 15° by stacking the silicon film system. This work is of great significance for the advancement of hyperspectral imaging and display technology.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131280"},"PeriodicalIF":2.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Juhan Lee, Seokhyeon Hong, Youngsoo Kim, Seung Hyeon Hong, Bokyung Kim, Soon-Hong Kwon
{"title":"Photonic physically unclonable functions using randomly positioned aluminum nanoholes","authors":"Juhan Lee, Seokhyeon Hong, Youngsoo Kim, Seung Hyeon Hong, Bokyung Kim, Soon-Hong Kwon","doi":"10.1016/j.optcom.2024.131273","DOIUrl":"10.1016/j.optcom.2024.131273","url":null,"abstract":"<div><div>With the advancement of the Internet of Things, the volume of information and communication has significantly increased, highlighting the critical need for enhanced data security. Physically unclonable functions (PUFs), which generate encryption keys through nondeterministic and replication-resistant methods, have been proposed as a solution. Among the various types of PUFs, optical-based PUFs are gaining attention owing to their ability to leverage light for rapid measurements and their superior resistance and complexity to replication compared to other methods. In this study, we proposed a photonic PUF based on an aluminum film structure with randomly positioned nanoholes on a substrate. Light transmission through this structure resulted in scattering owing to localized and propagating surface plasmon resonances. The resulting image was digitized to generate an encryption key. Our tests involved adjusting the filling factor (FF) and pixel size, yielding a high randomness of 49.87% and a high bit density of 1.6 × 10<sup>7</sup> bits/cm<sup>2</sup>. The independent bits produced a total of 258 bits, closely matching the actual bit count of 256 bits. Furthermore, applying a Gaussian distribution to the hole sizes, assuming a more realistic scenario, yielded favorable results. This structure is cost-effective owing to the simplicity of its materials, production method, and design. Additionally, its compact size of 40 μm × 40 μm makes it ideal for miniaturization and integration into various applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131273"},"PeriodicalIF":2.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
{"title":"Lamellar beam with similar propagation and imaging characteristics to a Bessel beam","authors":"Guangjun Yin, Qi Wang, Qing Lu, Yuanqing Wang","doi":"10.1016/j.optcom.2024.131275","DOIUrl":"10.1016/j.optcom.2024.131275","url":null,"abstract":"<div><div>A lamellar beam is proposed and investigated. Based on the Fresnel diffraction integral, the propagation of the beam in free space has been studied. Meanwhile, the non-diffracting and self-reconstructing properties of the beam are verified through an efficient and user-friendly optical design. We built a microscopic imaging system and used the lamellar beam for illumination, obtained a 200 × 200 pixels micrograph of a 1 mm thick sample containing fluorescent beads. We obtained a micrograph with a resolution of 1 μm, which is better than using a Gaussian beam and comparable to using a Bessel beam but spent less than a third of the time it would have taken when using Bessel beam.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131275"},"PeriodicalIF":2.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Yang Liu , Guangmang Cui , Shigong Shi , Weize Cui , Fu Liao , Jufeng Zhao
{"title":"Toward a fast and non-darkroom solution for speckle correlation based scattering imaging","authors":"Yang Liu , Guangmang Cui , Shigong Shi , Weize Cui , Fu Liao , Jufeng Zhao","doi":"10.1016/j.optcom.2024.131274","DOIUrl":"10.1016/j.optcom.2024.131274","url":null,"abstract":"<div><div>Speckle correlation-based scattering imaging is an ingenious field, as it allows for the efficient reconstruction of object images using computational techniques in a simple setup. However, this method typically necessitates high-contrast speckle images captured in a darkroom environment, restricting its applicability to specific scenarios. Here, we present a fast and non-darkroom imaging framework, namely FNDI, for reconstructing objects through scattering media under ambient light interference. Specifically, a speckle illumination model is established guided by the total variational Retinex (TV-Retinex) theory, and the speckle illumination component is adjusted to obtain an enhanced speckle with significantly improved contrast. Then, a modified Fienup algorithm with the iteration-driven shrinkwrap (IDS) strategy is employed to rapidly reconstruct the object image through tens of iterations. Extensive experiments are conducted under different lighting conditions to evaluate FNDI in comparison with existing non-darkroom methods and the classical speckle correlation method. The results demonstrate that FNDI is effective and efficient, making it highly attractive for practical scattering imaging applications.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131274"},"PeriodicalIF":2.2,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Aswathy Vijay , Nijas Mohamed , Pawan Kumar , Manjoosha Y. R , Jyothika V. G , Renu John
{"title":"An integrated portable system for laser speckle contrast imaging and digital holographic microscopy","authors":"Aswathy Vijay , Nijas Mohamed , Pawan Kumar , Manjoosha Y. R , Jyothika V. G , Renu John","doi":"10.1016/j.optcom.2024.131240","DOIUrl":"10.1016/j.optcom.2024.131240","url":null,"abstract":"<div><div>A multimodal quantitative phase imaging platform combining digital holographic microscopy (DHM) with laser speckle contrast imaging (LSCI) is demonstrated for imaging weakly scattering and transparent samples in a label-free manner. It uses the principle of coherence of the light source for interferometric detection of phase of transparent and semi-transparent samples. The speckle formation resulting from the coherence property of the laser source is used to track dynamic activities in the regions of interest in the sample. Integration of these two techniques onto a microfluidic chip leads to an optofluidic real-time microscope for live cell imaging applications. In this work, we have developed an integrated multimodal system combining digital holographic microscopy and laser speckle contrast imaging system for Optofluidics and in vitro studies. The sample flowing through the microfluidic channel is imaged to record holograms and video of intensity images at the same time. This enables to map the flow within a microfluidic channel and quantify the channel as well as the particle flow through the channel. The channel morphology along with the particles flowing through the channel are quantified using DHM. The two-dimensional speckle contrast images map the flow of the dynamic microbeads and cells with very high contrast in almost real time. A low-cost portable multimodal quantitative phase microscope combining DHM and LSCI has been demonstrated for real time imaging with applications in optofluidics.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131240"},"PeriodicalIF":2.2,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
{"title":"Loss-less passive polarization rectifier design with minimal etendue and size increase","authors":"Armen Zohrabyan , Aram Bagramyan , Tigran Galstian","doi":"10.1016/j.optcom.2024.131269","DOIUrl":"10.1016/j.optcom.2024.131269","url":null,"abstract":"<div><div>We describe an approach allowing the passive rectification of the polarization of light with approximately the same beam size, minimal increase of the etendue of the beam and with negligible reduction of its power. This is done for arbitrary (including chaotic) input polarization states and without their prior identification. The tradeoff is the partial increase of the angular spectrum of light. Theoretical estimations are provided along with some preliminary experimental results describing the possible use of this approach with large diameter beams as well as in optical fibers.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131269"},"PeriodicalIF":2.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
{"title":"Propagation of Sine hyperbolic Gaussian vortex beam (ShGvB) in vertical anisotropic oceanic turbulence with adaptive optics correction","authors":"Athira T. Das , R. Rajesh , Pramod Gopinath","doi":"10.1016/j.optcom.2024.131260","DOIUrl":"10.1016/j.optcom.2024.131260","url":null,"abstract":"<div><div>The propagation of Sinh Gaussian vortex beam (ShGvB) along vertical anisotropic oceanic turbulence is established using the spatial power spectrum which depends upon the depth of the ocean. The average intensity of the beams has been derived. For 100 m depth, the average intensity has been plotted and studied using the measured salinity and temperature from the ocean in both isotropic and anisotropic oceanic turbulence systems. The average transmittance of the ShGvB is studied and found that the beam degrades faster in anisotropic media than in isotropic media. To mitigate the aberrations adaptive optics (AO) correction is incorporated in the study along the vertical link. Quantitative estimates of the Bit error rate (BER) have been made to evaluate the beam's performance for vertical underwater optical communication and found that by improving the signal-to-noise ratio and incorporating AO, the ShGvB performs effectively in vertical underwater optical communication.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":"575 ","pages":"Article 131260"},"PeriodicalIF":2.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}