Article
Computer Science, Information Systems
Mohammed Elamassie, Murat Uysal
Summary: This study proposes a feedback-free adaptive modulation selection algorithm for Free Space Optical (FSO) communication systems, which aims to maximize average throughput by selecting the largest modulation order while ensuring that the required transmit power does not exceed the maximum power. Numerical results confirm the superiority of the proposed adaptive algorithm.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Mehtab Singh, Somia A. Abd El-Mottaleb, Syed Alwee Aljunid, Hassan Yousif Ahmed, Medien Zeghid, Kottakkaran Sooppy Nisar
Summary: This paper presents a new hybrid system that combines multi-mode fiber (MMF) with free space optics (FSO) using orbital angular momentum (OAM) multiplexing for high-bandwidth and high-transmission-capacity communication. The system achieves simultaneous transmission of 40 Gb/s data on four distinct OAM beams with a single wavelength, with a symmetric circular shape. The performance of the system was evaluated under different weather conditions and atmospheric turbulences, and the results demonstrate its capability to transmit data up to 1250 m under clear weather and weak turbulence, with a minimum transmission distance of 440 m under heavy fog. The system's performance was also demonstrated based on actual meteorological data for two different cities, Alexandria and Chandigarh, with the obtained ranges within an acceptable bit error rate for supporting symmetric 40 Gb/s data in next generation passive optical networks (PON).
RESULTS IN PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Ali Refaai, Fatma Newagy, Mohamed Fathy Abo Sree, Moustafa H. Aly, Hadia Elhennawy, Mohamed Abaza
Summary: Optical space communication in the form of a relay satellite system using laser satellite communication (SatCom) is proposed to overcome the challenges of RF satellite communication. Channel turbulence, additional technologies, intensity modulation direct detection (IM/DD), decoding, and forwarding (DF) are employed to evaluate the efficacy of the proposed laser uplink satellite relay communication model in terms of outage probability (OP) and bit error rate (BER) indicators. The study analyzes the necessary channel properties and compares the findings with those of optical direct link to demonstrate the superiority of the proposed system. The investigation of system parameters reveals that the proposed system outperforms optical downlink SatCom, improving the required aperture radius by up to 10% and the overall system performance by up to 57%.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
M. Shariful Islam, S. P. Majumder
Summary: This research article investigates the impact of atmospheric turbulence and polarization crosstalk on the performance of a non-Hermitian OFDM FSO system. The results show the power penalty and receiver sensitivity vary under different turbulence conditions.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Optics
M. Vinoth Kumar, Vinod Kumar
Summary: This work introduces a scheme for transmitting dual-polarized quadrature amplitude modulated (QAM) signals through a sixteen-channel wavelength division multiplexing (WDM) and free-space optics (FSO) communication link, achieving a transmission rate of 120 Gbps per channel. The system's performance is evaluated by calculating atmospheric attenuations in different weather conditions and compared to previous reports.
JOURNAL OF MODERN OPTICS
(2022)
Article
Optics
Yufei Luo, Yalong Hai, Anhong Dang
Summary: This paper focuses on accurately characterizing the performance of TCP over FSO links. By introducing a second-order Markovian assumption and proposing a Markov chain model, the TCP operations are interpreted and the throughput efficiency is formulated. The proposed model is validated through simulations and experiments, and the impact of different parameters on TCP performance is analyzed.
Article
Engineering, Electrical & Electronic
Malik Mubasher Hassan, Ghulam Mohammad Rather
Summary: This research proposes an innovative Selective Active Relay (SAR) protocol, introduces the Water Pouring Erbium-Doped Fiber Amplifier (WPEDFA) method and Optimum Enhanced African Buffalo (OE-AB) algorithm to optimize FSO communication quality, reducing the bit error rate and outage probability.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Haibo Wang, Zaichen Zhang, Bingcheng Zhu, Jian Dang, Liang Wu
Summary: This article investigates the performance of an ORIS-assisted hybrid RF and FSO communication system. By considering the physical models of ORIS, RF channel, atmospheric turbulence, and pointing error, closed-form solutions for the system's outage probability and BER have been derived. The results show that RF-FSO links with ORISs perform slightly worse than traditional RF-FSO links, but the performance degradation introduced by ORIS is relatively small, and the FSO link benefits from a higher degree of beam adjustment freedom.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2022)
Article
Computer Science, Information Systems
Jeremiah Oluwatosin Bandele, Ayodeji Olalekan Salau, Mmoloki Mangwala, Adamu Murtala Zungeru
Summary: This paper investigates the impact of using multiple transmitters in preamplified FSO communication links limited by strong atmospheric turbulence, amplified spontaneous emission noise, fixed path loss, and pointing errors. The results show that increasing the number of transmitters can improve BER performance, especially in the presence of severe pointing errors.
Article
Multidisciplinary Sciences
Hai-Han Lu, Chung-Yi Li, Wen-Shing Tsai, Poh-Suan Chang, Yan-Yu Lin, Yu-Ting Chen, Chen-Xuan Liu, Ting Ko
Summary: This study successfully constructs a two-way fibre-FSO converged system through 25 km single-mode fibre and 500 m free-space transmission. By incorporating dual-wavelength four-level pulse amplitude modulation and polarisation-multiplexing mechanism, the transmission capacity is significantly enhanced to 224 Gbit/s with excellent transmission performance.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Kanchan Sharma, Surender K. Grewal
Summary: This paper investigates a free space optical communication system using a hybrid modulation technique in weak turbulence conditions. It derives the analytical average bit error rate and closed form expression of the hybrid modulation scheme, showing excellent agreement with simulation results.
Article
Optics
Yang Cao, Wenqing Li, Jing Zhang, Xiaofeng Peng, Yue Li
Summary: This paper proposes a segmented turbulent partial order construction method to solve the high complexity issue of polarization code construction in free-space optical communication. By introducing the generalized partial order technique and utilizing Monte Carlo simulation, the method determines the reliability relationship between sub-channels in strong turbulence and constructs the polarization code with optimal parameter values based on different signal-to-noise ratio ranges. The simulation results demonstrate similar communication performance compared to the conventional Monte Carlo method, with negligible construction complexity.
Article
Telecommunications
Mohammed Elamassie, Sadiq M. Sait, Murat Uysal
Summary: In this paper, we investigate a multiple-input multiple-output (MIMO) free space optical (FSO) communication system with intensity modulation and direct detection (IM/DD) under Gamma-Gamma (GG) turbulence channels in the presence of pointing errors. We derive an approximate expression for the finite-SNR diversity order and analyze the convergence speed to full diversity. Numerical results are provided to demonstrate the accuracy of our derivations and confirm our analytical findings.
IEEE COMMUNICATIONS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Prakriti Saxena, Yeon Ho Chung
Summary: This paper investigates the impact of jamming from a malicious UAV on the performance of a FSO communication system using a legitimate UAV as a relay and an IRS for coverage improvement. The effects of atmospheric turbulence, pointing error, and angle of arrival fluctuations are statistically characterized. Closed-form expressions for the overall ABER and OP are derived, and different locations of the jammer and IRS are considered for a comprehensive study. The analytically derived expressions are verified through Monte-Carlo simulations.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Engineering, Multidisciplinary
Mehtab Singh, Ahmad Atieh, Moustafa H. Aly, Somia A. Abd El-Mottaleb
Summary: This article introduces a novel 120 Gbps free space optics (FSO) transmission scheme that combines orbital angular momentum (OAM) multiplexed signals with spectral amplitude coded (SAC) optical code division multiplexing access (OCDMA) technique. By utilizing four OAM beams, each carrying three independent channels, the capacity of the FSO system is increased to 120 Gbps. Experimental results demonstrate that under different weather conditions, including clear air, varying levels of rain, haze, and fog, longer propagation distances can be achieved with a low bit error rate (BER).
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Ehsan Ahmadinejad, Mohammd H. Mahdieh
Summary: In this study, Ag-Au alloy nanoparticles were successfully synthesized by post-irradiation with nanosecond pulse laser in the presence of an external electric field. The results showed that the electric field significantly reduced the formation time of Ag-Au alloy and decreased the localized surface plasmon resonance wavelength of the alloy nanoparticles.
JOURNAL OF NANOPHOTONICS
(2021)
Article
Chemistry, Physical
Mohsen Bonjakhi, Mohammad Hossein Mahdieh
Summary: In this study, pulsed laser deposition was used to fabricate Ag nanoparticle films in open air without flowing gas. The films were characterized using FESEM, HRTEM, and UV/Vis absorption spectroscopy, and the surface plasmon resonance characteristics were extracted from the UV/Vis spectrum. The fabricated NP films showed significant enhancement in Raman signals, demonstrating their potential application in sensors.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Materials Science, Multidisciplinary
Ehsan Ahmadinejad, Mohammad Hossein Mahdieh
Summary: The present study aimed to synthesize colloidal Ag-Cu alloy nanoparticles with unique antibacterial and antimicrobial activities, and found that the external electric field can improve the stability and size of the alloy nanoparticles.
JOURNAL OF LASER APPLICATIONS
(2022)
Article
Optics
Seyed Peyman Abbasi, Mohammad Hossein Mahdieh
Summary: In this research, the electro-optical characteristics of slab coupled optical waveguide diode lasers were significantly improved by using a broadened waveguide with linear graded refractive index profile and optimized doping. The addition of asymmetric barrier in the sides of active region resulted in a decrease in threshold current and an increase in slope efficiency (SE). The proposed structure showed a 12% higher power conversion efficiency (PCE) and a 0.21 W/A higher slope efficiency (SE) compared to conventional step profile designs.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Seyed Peyman Abbasi, Mitra Goodarzi, Mohammad Hossein Mahdieh
Summary: This paper introduces a diode laser design method based on the optimization of the thickness and material composition of the quantum well (QW) to achieve the minimum current threshold and maximum output optical power. An asymmetric waveguide structure is used to control the confinement factor and reduce free carrier loss. Experimental results show that the proposed design effectively enhances optical power and improves slope efficiency.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Physics, Multidisciplinary
R. B. Kian, M. H. Mahdieh
Summary: This paper investigates the nonlinear propagation of dust acoustic solitary waves (DASWs) in an unmagnetized dusty plasma consisting of negatively charged dust fluid, Boltzmann distributed electrons with two different temperatures, and Boltzmann distributed ions with two distinct temperatures. The results reveal that the main quantities of DASWs are affected by the temperature of electrons and ions, as well as the temperature ratio and number densities of ions.
PHYSICS OF WAVE PHENOMENA
(2022)
Article
Materials Science, Multidisciplinary
Mohammad Hossein Mahdieh, Mehrad Sohrabi
Summary: Using three theoretical models and experimental results, a set of refractive index data for VO2 thin films with thickness dependence is provided. This data can be used to calculate more precise transmission and determine the optimal film thickness for any desired transmission performance. This method is useful for designing VO2-based thermochromic smart windows.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Multidisciplinary
Rasool Barazandeh Kian, Mohammad Hossein Mahdieh
Summary: The propagation of large amplitude dust acoustic solitary waves in an unmagnetized dusty plasma was investigated. It was found that both non-thermal electron and ion parameter significantly modify the basic properties of the waves. Furthermore, an increase in Mach number leads to an increase in the amplitude of the waves.
PHYSICS OF WAVE PHENOMENA
(2022)
Article
Physics, Fluids & Plasmas
R. B. Kian, M. H. Mahdieh
Summary: Using the Sagdeev pseudo-potential method, this study theoretically investigates dust acoustic solitary waves (DASWs) in a magnetized dusty plasma. The research finds that the coexistence of positive and negative potential occurs in such dusty plasma.
PLASMA PHYSICS REPORTS
(2022)
Article
Mechanics
Rasool Barazandeh Kian, Mohammad Hossein Mahdieh
Summary: The propagation of dust acoustic solitary waves (DASWs) in a magnetized dusty plasma comprising of negatively charged dust particles, nonthermal ions and nonthermal electrons was investigated. The Korteweg-de-Vries (K-dV) equation was derived using reductive perturbation method. It was found that the basic structures of DASWs are influenced by nonthermal ions and nonthermal electrons. Both compressive and rarefactive DASWs exist in such dusty plasma. The nonthermality parameter of ions and electrons affects the non-linear wave phase velocity, with ions having a greater effect than electrons. The angle between the external magnetic field and the wave propagation direction strongly influences the amplitude and width of DASWs. The magnetic field only affects the width and not the amplitude of DASWs.
FLUID DYNAMICS RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Mohsen Bonjakhi, Mohammad Hossein Mahdieh
Summary: In this study, Ag nanoparticle films were fabricated by pulsed laser deposition technique in the flowless atmospheric air. The characteristics of the films were investigated after postirradiation by pulsed laser beam, and thermal annealing in argon gas flow. The results show that thermal annealing leads to enhancement of the films' surface plasmon resonance (SPR) characteristics and the annealed films exhibit better performance in surface-enhanced Raman spectroscopy (SERS) application.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Fluids & Plasmas
R. B. Kian, M. H. Mahdieh
Summary: Nonlinear dust acoustic solitary waves in an unmagnetized dusty plasma with a negatively charged dust fluid are studied in bounded 2D cylindrical geometry. The modified Korteweg-de Vries equation for cylindrical geometry is derived and its exact solution is obtained. The trapped ions have significant effect on the properties of the waves in cylindrical geometry.
PLASMA PHYSICS REPORTS
(2023)
Article
Physics, Fluids & Plasmas
R. B. Kian, M. H. Mahdieh
Summary: The dispersion relation and instability of dust acoustic waves (DAWs) in an unmagnetized dusty plasma with two different temperatures for ions, two different temperatures for electrons, and dust charge fluctuations are studied. The effects of two different temperatures of ions (electrons), dust charge fluctuations, density ratio of ions, and density ratio of electrons significantly modify the conditions for instability. Furthermore, it is observed that only damping rate exists in such a dusty plasma.
PLASMA PHYSICS REPORTS
(2023)
Article
Physics, Multidisciplinary
M. H. Mahdieh, M. S. Asl
Summary: This study measured the M-2 factor of a He-Ne probe beam influenced by the thermal lens effect in liquid ethanol. The results showed that the beam quality factor M-2 of He-Ne increased nonlinearly with the increase of diode laser power. These findings are significant for applications like laser ablation in liquid (LAL) where beam quality and focused size are important, and highlight the need to consider the thermal lens effect induced by high-power laser beams.
INDIAN JOURNAL OF PHYSICS
(2023)
Article
Instruments & Instrumentation
B. Mohammadfam, M. H. Mahdieh, H. Veladi
Summary: In this work, we fabricate a compact optical displacement sensor based on whispering gallery mode using common materials PDMS and mold master technique, and demonstrate its feasibility for sensing applications. The sensor structure allows for high-resolution sensing of micron-level displacement by adjusting the coupling junction, and sensing of refractive index by controlling the concentration of the active medium.
JOURNAL OF INSTRUMENTATION
(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)
