Article
Engineering, Electrical & Electronic
Tanoy Kumar Dey, Sara Tombelli, Palas Biswas, Ambra Giannetti, Nandini Basumallick, Francesco Baldini, Somnath Bandyopadhyay, Cosimo Trono
Summary: A long period fiber grating sensor with maximum enhancement of the evanescent field working with the lowest order cladding mode has been fabricated and analyzed in terms of dual peak resonance wavelengths and coupling conditions. The sensitivity of the sensor to surrounding refractive index was measured to be 8751 nm/SRIU with a resolution of 10(-5) within a specific SRI range.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Analytical
Tanoy Kumar Dey, Sara Tombelli, Arpan Roy, Palas Biswas, Ambra Giannetti, Nandini Basumallick, Francesco Baldini, Somnath Bandyopadhyay, Cosimo Trono
Summary: A new methodology to enhance the sensitivity of a long period fiber grating sensor (LPFG) at the Turn Around Point (TAP) has been presented. The LPFG sensor was fabricated by etching the fiber up to 20.4 μm, until the sidelobes of dispersed LP0,2 cladding mode appeared near TAP in aqueous medium. The dual peak sensitivity of the sidelobes was found to be 16,044 nm/SRIU (surrounding refractive index units) in the RI range from 1.333 to 1.3335.
Article
Chemistry, Analytical
Shimeng Chen, Chao Zhang, Jiahui Wang, Na Li, Yongxin Song, Haojun Wu, Yun Liu
Summary: A fiber-optic biosensing platform based on ultra-narrowband cladding mode resonances was developed using a high-reflectivity fiber Bragg grating (FBG) for targeted biomolecular detection. Multiple cladding modes with high sensitivity to refractive index (RI) were excited in the FBG through coupling between the guided core mode of a multimode fiber and the guided cladding mode of the FBG. The proposed FBG sensor demonstrated superior performance in terms of sensitivity and selectivity, and the sensitivity was further enhanced by coating graphene oxide (GO) sheets on the sensing surface.
Article
Engineering, Electrical & Electronic
Tanoy Kumar Dey, Palas Biswas, Nandini Basumallick, Somnath Bandyopadhyay
Summary: In this study, an experimental investigation on the add-layer sensitivity of LP0,11 cladding mode (CM) near the turn around point (TAP) of Long Period Fiber Grating (LPFG) was conducted. A sensitivity of 2.308 nm(WL)/nm(TH) was achieved, which is similar to the sensitivity near the mode transition (MT). The sensor designed based on this methodology overcomes the limitations of operating a CM near MT, such as loss of contrast of the resonant band and limited dynamic range, and has a dynamic range of approximately 100 nm with contrast greater than -10 dB throughout the measurement range, which is practically impossible for CM operating at MT.
IEEE SENSORS JOURNAL
(2021)
Article
Chemistry, Analytical
Tiansheng Huang, Qiangqiang Fu, Li-Peng Sun, Peiyuan Liu, Ze Wu, Kaqiang Li, Ruitao Xiao, Xiao Yang, Yan Huang, Wenfu Lin, Hanglin Lu, Jun Ma, Wei Wang, Jie Li, Yong Tang, Bai-Ou Guan
Summary: The study demonstrated a microfiber long-period grating (mLPG) based biosensor for lateral flow immunoassay to enhance detection limit and range. The mLPG showed strong evanescent wave functions and was sensitive in detecting refractive index changes induced by gold nanoparticles. The technique proved to be sensitive, easy-to-use, and effective in analyzing trace chemicals or biochemicals for various applications.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Engineering, Electrical & Electronic
Ke Tian, Zhiyuan Zhao, Mingyuan Zhang, Meng Zhang, Elfed Lewis, Gerald Farrell, Pengfei Wang
Summary: This article describes a novel long-period fiber grating (LPFG) sensor based on a core-cladding misalignment structure. The LPFG, consisting of multiple short-length singlemode fiber (SMF) segments joined with core-cladding misalignment splicing, allows for periodic refractive index modulation along the fiber axis. The experimental investigation demonstrates that the LPFG sensor has high sensitivities for refractive index, strain, and temperature, making it suitable for accurate measurement and sensing in industrial and harsh environments.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Duarte Viveiros, Jose Manuel Marques Martins de Almeida, Luis Coelho, Helena Vasconcelos, Joao M. Maia, Vitor A. Amorim, Pedro A. S. Jorge, Paulo V. S. Marques
Summary: A detailed study was conducted on turn around point long period fiber gratings with coupling to asymmetric cladding modes, fabricated using femtosecond laser direct writing. The fabrication process, coating with TiO2 film, and necessary corrections to achieve TAP condition with optimized sensitivity to the surrounding refractive index were discussed. LPFGs were coated with different thicknesses of TiO2 film and analyzed for wavelength sensitivity, showing maximum sensitivity when coated with a 30 nm thick film.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Dandan Liao, Yuehui Ma, Chen Jiang, Chengbo Mou, Yunqi Liu
Summary: This study demonstrates the inscription of long-period gratings (LPGs) in a fluorine-doped double-cladding fiber (DCF) with a low refractive index trench. The research investigates the transmission spectra and cladding mode evolution of the DCF-LPG during the cladding etching process. It is found that the mode order of the cladding modes decreases while the resonance wavelength of the DCF-LPG remains stable. Experimental results show that the proposed DCF-LPG has a higher torsion sensitivity and potential application as a tunable band-rejection filter in broad wavebands.
OPTICS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Xinghu Fu, Jiahao Zhou, Zizhen Fu, Ming Xu, Shuming Huang, Wa Jin, Guangwei Fu, Weihong Bi
Summary: A multi-parameter sensor based on dumbbell-shaped double-cladding fiber structure cascaded long period fiber grating is proposed. It can measure temperature, refractive index, and axial strain by demodulating the wavelength shift of the resonant peaks. The experimental results show that the sensor has high sensitivity and resolution.
IEEE SENSORS JOURNAL
(2022)
Article
Biophysics
Flavio Esposito, Lucia Sansone, Anubhav Srivastava, Francesco Baldini, Stefania Campopiano, Francesco Chiavaioli, Michele Giordano, Ambra Giannetti, Agostino Iadicicco
Summary: In this study, a novel fiber-optic biosensor was developed and tested for label-free detection of C-reactive protein in serum. The device showed enhanced sensitivity and visibility of grating resonances by tuning the working point to the mode transition region through etching of the outer fiber cladding. Coating the fiber transducer with graphene oxide enabled covalent immobilization of the biological recognition element, resulting in a low detection limit and a wide working range of clinical relevance.
BIOSENSORS & BIOELECTRONICS
(2021)
Article
Chemistry, Analytical
Flavio Esposito, Lucia Sansone, Anubhav Srivastava, Angela Maria Cusano, Stefania Campopiano, Michele Giordano, Agostino Iadicicco
Summary: This study presents a fiber optic biosensor for label-free detection of vitamin D3, showing good sensitivity and stability in both laboratory and complex media.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Engineering, Electrical & Electronic
Gaia Maria Berruti, Patrizio Vaiano, Alessandra Boniello, Sofia Principe, Giuseppe Quero, Giovanni Vito Persiano, Marco Consales, Andrea Cusano
Summary: In this study, we demonstrate the use of TAP LPG as a resonant core-to-cladding light coupling mechanism for the fabrication of a highly efficient heating device based on metallic coated FBG. Comparing with other coupling components, the TAP LPG-based device exhibits an actuation efficiency 2.5 times greater, making it the most effective and highly performing solution for energy transfer.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Qiang Ling, Jihong Tao, Zhengtian Gu, Wenyu Wu
Summary: This paper proposes a few-mode cladding-reduced long period fiber grating (FM-CRLPFG) sensor fabricated by using CO2 laser to improve the sensitivity of the surrounding refractive index (SRI) measurement. The experiment shows that reducing the cladding radius effectively enhances the SRI sensitivity.
Article
Chemistry, Analytical
Tanoy Kumar Dey, Cosimo Trono, Palas Biswas, Ambra Giannetti, Nandini Basumallick, Francesco Baldini, Somnath Bandyopadhyay, Sara Tombelli
Summary: This study presents a methodology to enhance the sensitivity of long-period fiber gratings (LPFGs) by combining three different enhancement approaches, including working near mode transition (MT) of a cladding mode (CM), working near the turn-around point of a CM, and enhancing the evanescent field of CMs by reducing the cladding diameter or increasing the order number of CMs. An electrostatic self-assembly (ESA) process was used to deposit a polymeric overlay with a chosen thickness onto the etched fiber to combine these enhancement methodologies. The effectiveness of the applied methodology for sensitivity enhancement was demonstrated by performing an IgG/anti-IgG immunoassay in human serum in a thermostated microfluidic system, with limits of detection (LODs) calculated to be 6.9 x 10^(-8) & mu;g/mL and 4.5 x 10^(-6) & mu;g/mL using different procedures.
Article
Chemistry, Analytical
Seul-Lee Lee, Jihoon Kim, Sungwook Choi, Jinsil Han, Giwan Seo, Yong Wook Lee
Summary: The study demonstrated label-free detection of SARS-CoV-2 spike protein using a PS-LPFG conjugated with SARS-CoV-2 spike antibodies. The sensor showed specific spectral changes at different protein concentrations, indicating its potential for clinical applications.
Article
Cardiac & Cardiovascular Systems
Claudia Kusmic, Alessio Vizzoca, Monia Taranta, Lorena Tedeschi, Lisa Gherardini, Gualtiero Pelosi, Ambra Giannetti, Sara Tombelli, Settimio Grimaldi, Francesco Baldini, Claudio Domenici, Maria Giovanna Trivella, Caterina Cinti
Summary: Cardiac hypertrophy, especially with myocardial fibrosis, can lead to heart failure. Survivin (SURV) overexpression is a hallmark of heart failure, but its function in the heart is not fully understood. Targeting SURV and OPN mRNAs with therapeutic molecules showed promise in treating hypertrophic cardiomyocytes.
JOURNAL OF CARDIOVASCULAR TRANSLATIONAL RESEARCH
(2022)
Article
Biochemical Research Methods
Sara Tombelli, Cosimo Trono, Simone Berneschi, Chiara Berrettoni, Ambra Giannetti, Romeo Bernini, Gianluca Persichetti, Genni Testa, Guillermo Orellana, Francesca Salis, Susanne Weber, Peter B. Luppa, Giampiero Porro, Giovanna Quarto, Markus Schubert, Marcel Berner, Paulo P. Freitas, Susana Cardoso, Fernando Franco, Vania Silverio, Maria Lopez-Martinez, Urs Hilbig, Kathrin Freudenberger, Gunter Gauglitz, Holger Becker, Claudia Gartner, Mark T. O'Connell, Francesco Baldini
Summary: This paper describes a compact point of care optical device for therapeutic drug monitoring, utilizing immunoassays in disposable plastic chips to detect multiple analytes simultaneously with high efficiency. The device is equipped with a microfluidic system and thin film amorphous silicon photodiodes for fluorescence detection, improving the speed and sensitivity of the assay.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Article
Engineering, Electrical & Electronic
Shir Rabi, Sara Meir, Raphi Dror, Hamootal Duadi, Francesco Baldini, Francesco Chiavaioli, Moti Fridman
Summary: In this study, we experimentally demonstrate a ghost imaging method in the frequency domain using frequency speckle patterns as references. Our method is suitable for high repetition rate ultrafast signal spectral measurements. We investigate the influence of signal periodicity and speckle size on reconstruction resolution, and propose a simple, broadband approach that utilizes a low-cost detector.
IEEE PHOTONICS JOURNAL
(2022)
Article
Chemistry, Analytical
Tanoy Kumar Dey, Sara Tombelli, Arpan Roy, Palas Biswas, Ambra Giannetti, Nandini Basumallick, Francesco Baldini, Somnath Bandyopadhyay, Cosimo Trono
Summary: A new methodology to enhance the sensitivity of a long period fiber grating sensor (LPFG) at the Turn Around Point (TAP) has been presented. The LPFG sensor was fabricated by etching the fiber up to 20.4 μm, until the sidelobes of dispersed LP0,2 cladding mode appeared near TAP in aqueous medium. The dual peak sensitivity of the sidelobes was found to be 16,044 nm/SRIU (surrounding refractive index units) in the RI range from 1.333 to 1.3335.
Article
Chemistry, Analytical
Tanoy Kumar Dey, Cosimo Trono, Palas Biswas, Ambra Giannetti, Nandini Basumallick, Francesco Baldini, Somnath Bandyopadhyay, Sara Tombelli
Summary: This study presents a methodology to enhance the sensitivity of long-period fiber gratings (LPFGs) by combining three different enhancement approaches, including working near mode transition (MT) of a cladding mode (CM), working near the turn-around point of a CM, and enhancing the evanescent field of CMs by reducing the cladding diameter or increasing the order number of CMs. An electrostatic self-assembly (ESA) process was used to deposit a polymeric overlay with a chosen thickness onto the etched fiber to combine these enhancement methodologies. The effectiveness of the applied methodology for sensitivity enhancement was demonstrated by performing an IgG/anti-IgG immunoassay in human serum in a thermostated microfluidic system, with limits of detection (LODs) calculated to be 6.9 x 10^(-8) & mu;g/mL and 4.5 x 10^(-6) & mu;g/mL using different procedures.
Article
Materials Science, Multidisciplinary
Francesco Chiavaioli, Desiree Santano Rivero, Ignacio Del Villar, Abian B. Socorro-Leranoz, Xuejun Zhang, Kaiwei Li, Enrique Santamaria, Joaquin Fernandez-Irigoyen, Francesco Baldini, Daniel L. A. van den Hove, Lei Shi, Wei Bi, Tuan Guo, Ambra Giannetti, Ignacio R. Matias
Summary: Alzheimer's disease (AD) is a neurodegenerative disease with high mortality rate among the elderly. Current diagnostic systems lack sensitivity, reproducibility, accuracy, and specificity. This study presents a lab-on-fiber (LoF) technology using a D-shaped single-mode fiber combined with nanometer-scale metal-oxide film for AD biomarker detection. The proposed sensing system increases the interaction between the fiber and surrounding medium, achieving highly sensitive detection of Tau protein, a classical AD biomarker. The LoF biosensor offers a promising solution for early screening and personalized medicine in AD.
ADVANCED PHOTONICS RESEARCH
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Maxime Lobry, Hadrien Fasseaux, Mederic Loyez, Karima Chah, Erik Goormaghtigh, Francesco Baldini, Ruddy Wattiez, Christophe Caucheteur, Francesco Chiavaioli
Summary: Gold-coated tilted fiber Bragg gratings (TFBGs) have been extensively studied for biosensing purposes. A more sensitive demodulation technique based on gold-coated TFBG spectra has been introduced, and successfully applied for the detection of HER2 proteins. Practical improvements such as a uniform FBG and a microfluidic system make this sensing platform more attractive and promising for practical applications.
OPTICAL SENSING AND DETECTION VII
(2022)
Article
Optics
Zhi-Huan Pang, Meng Liu, Ai-Ping Luo, Yi Xu, Wen-Cheng Xu, Songnian Fu, Zhi-Chao Luo
Summary: We propose a novel mode-dependent gain equalizer using a few-mode chirped fiber Bragg grating (FM-CFBG) to effectively mitigate the mode-dependent gain in an all-fiber 2-mode EDFA. The equalizer based on FM-CFBG offers compact size, low insertion loss, and wavelength scalability, making it meaningful for long-haul MDM transmission.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Yiwei Qiu, Chenliang Ding, Gangyao Zhan, Mengdi Luo, Jisen Wen, Mengbo Tang, Chun Cao, Wenjie Liu, Liang Xu, Bihu Lv, Dazhao Zhu, Cuifang Kuang, Xu Liu
Summary: This article proposes a novel method to simultaneously reduce the axial and lateral feature sizes of PPI-DLW. By employing a pseudo 3D hollow focus, a suspended nanowire with an isotropic 30-nm feature size was realized, thereby improving the capabilities of PPI-DLW for fabricating arbitrary 3D structures.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Manzhuo Wang, Jianbo Yue, Zhentao Yao, Tingyu Liu, Xiaoqiang Sun, Yuanda Wu, Daming Zhang
Summary: A silica waveguide 1×8 thermo-optic switch consisting of cascaded three-stage Mach-Zehnder interferometers (MZIs) is successfully demonstrated. The switch utilizes a multimode interference (MMI) coupler in the MMI-MZI 1×2 switch unit for its wavelength insensitivity and favorable fabrication tolerance. The switch design and optimization is based on the beam propagation method (BPM) and implemented using standard CMOS technologies. Experimental results show that the switch meets the requirements for insertion loss and crosstalk at 1550 nm wavelength, and also performs well in a wide wavelength range.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
H. M. de la Cruz, E. D. Hernandez-Campos, E. Ortiz-Ricardo, A. Martinez-Borquez, I. Rosas-Roman, V. Contreras, G. Ramos-Ortiz, B. Mendoza-Santoyo, Cecilia I. Zurita-Lopez, R. Castro-Beltran
Summary: Acoustic levitation is an important contactless manipulation technique in various fields. This study presents an affordable phased-array levitator that can stably trap micrometer dye-doped droplets in the air, enabling the creation of microlasers. The levitated microlasers exhibit comparable optical lasing features to On-a-Chip devices, with a maximum Q-factor of approximately 105 and a minimum lasing threshold of approximately 150 nJ cm-2.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Yuqi Wang, Zilong Zhang, Suyi Zhao, Wei He, Xiaotian Li, Xin Wang, Yuchen Jie, Changming Zhao
Summary: This paper investigates the impact of localized defects in SLM devices on structured light generation and demonstrates the reconstructed light field results under different defect states using CGH loaded onto the DMD. The results show that central defects have minimal influence on the reconstructed light field, while edge defects have a significant impact. This study expands the application scenarios for the generation of structured light beams with SLM.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Ashraf A. A. Beshr, Hossam El-Din Fawzy, Ehab A. A. Eldin, Jong Wan Hu, Fathi A. Abdelmgeed
Summary: This paper introduces the application of digital measuring techniques, specifically Digital Close Range Photogrammetry (DCRP), in the detection of deformation in post-tensioned structural elements (PTSEs). The use of digital equipment and a terrestrial laser scanner (TLS) allows for highly accurate monitoring of PTSE camber, with deviations not exceeding 0.01 mm.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Shihao Gou, Danping Huang, Shipeng Liao, Fan Luo, Yang Yuan, Liang Liu, Xiaomei Wen
Summary: This paper proposes an online intelligent detection method for cable pitch defects in the field of optical cable manufacturing. The method utilizes a multi-sensor fusion image acquisition platform and deep learning technology to achieve accurate detection of pitch defects in optical cables.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Tun-Yao Hung, David W. U. Chan, Ching-Wei Peng, Chi-Wai Chow, Hon Ki Tsang
Summary: We present the first experimental demonstration of a high-capacity short-reach optical communication link which utilizes LSTM and DNN to achieve 300 Gbit/s 8-level pulse amplitude modulation (PAM8) generated by a single microring modulator. The experimental results show that 300 Gbit/s and 270 Gbit/s PAM8 modulation can be achieved at back-to-back and after 1 km transmission respectively.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Long Zhang, Li Pei, Jianshuai Wang, Jingjing Zheng, Kaihua Hu, Zhiqi Li, Tigang Ning, Jing Li, Li Zhong, Ruisi He
Summary: The amplification of long-haul mode division multiplexing (MDM) transmission systems is currently achieved through three steps, which can result in complexity and degraded transmission performance. To address this issue, this paper proposes an in-line few-mode erbium-doped fiber amplifier (FM-EDFA) based on cladding pumping, which enables simultaneous amplification and transmission in MDM systems. Experimental results demonstrate that the in-line FM-EDFA has excellent performance and shows great potential for practical long-haul transmission systems.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Chong Wang, Miaomiao Li, Jiahao Yang, Bingli Zhu, Jianghao Han, Wenbin Dang
Summary: This paper introduces the design of drive circuits using step recovery diodes and RF bipolar transistors to produce narrow pulse lasers, achieving the reduction of system size, power consumption and cost.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Ziqian Zhang, Liangyu Zhao, Chaorun Si, Yang Tian, Shilin Xu
Summary: A Hastelloy C276 coating was prepared on a martensitic stainless-steel substrate using laser melting deposition, resulting in a coating with high resistance to cavitation erosion. The coating exhibited a thick, progressively changing grain morphology from bottom to top, and the grains grew in a specific angle to the substrate plane. A compositional mixing zone was formed at the interface, forming a stable metallurgical bond. The coating showed a significantly improved hardness and enhanced resistance to cavitation erosion compared to the substrate.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Cui-Hong Li, Chao-Xiong He, Yuan-Yuan Ma, Jin-Chuan Wang, Ying Dong, Shao-Chong Zhu, Xiao-Wen Gao, Hui-Zhu Hu
Summary: In this paper, a non-contact optical measuring method for characterizing nanoparticles using optical tweezers is presented. The method relies on the optical polarization and scattering of nanoparticles, providing insights into both shape and size parameters. Experimental results show that the method can accurately measure the shape and size of nanoparticles, making it an effective tool for identifying and studying individual nanoparticles.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Magdalena Zieba, Cuma Tyszkiewicz, Katarzyna Wojtasik, Krystian Pavlov, Pawel Chaber, Ewa Gondek, Jacek Niziol, Roman Rogozinski, Pawel Kielan, Pawel Karasinski
Summary: This work presents a study on low-loss waveguide layers for planar evanescent wave sensor applications. Crack-free SiOx:TiOy composite layers with refractive indices of approximately 1.65 were fabricated using a sol-gel method and dip-coating technique. The fabricated layers exhibited good waveguide properties and optical homogeneity.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Yali He, Jiao Tang, Zhongyang Li, Yaowu Hu
Summary: In this paper, a lithography-free broadband absorbing metasurface consisting of Ag nanoparticles with ultrafine nanogaps is demonstrated. The experimental results and numerical simulations show that the horizontally compressed Ag nanoparticles possess smaller nanogaps for high sensitivity, uniformity, and stability. The novel substrate also exhibits insensitivity to the incident or observation angle in an ambient environment and has promising practical applications.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Optics
Linqing Li, Chengwei Yang, Zhuo Wang, Kun Xiao, Rui Min
Summary: In this study, a stretchable polymer optical fiber with a sandwich structure was proposed for sleep monitoring. The fiber improved the pressure sensitivity of the mattress and enabled the measurement of respiratory rate, heart rate, and body motion information.
OPTICS AND LASER TECHNOLOGY
(2024)
