3,956 results match your criteria dual wavelength

Polarization-transparent silicon photonic add-drop multiplexer with wideband hitless tuneability.

Nat Commun 2021 Jul 15;12(1):4324. Epub 2021 Jul 15.

Dipartimento di Elettronica, Informazione e Bioingegneria, Milano, Italy.

Flexible optical networks require reconfigurable devices with operation on a wavelength range of several tens of nanometers, hitless tuneability (i.e. transparency to other channels during reconfiguration), and polarization independence. Read More

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Single- and dual-wavelength fiber laser with multi-transverse modes.

Opt Express 2021 Jun;29(13):20299-20306

A single- and dual-wavelength fiber laser with multi-transverse modes is proposed. Mode interference is realized in the core of an optical fiber by writing a long period fiber grating on a few-mode fiber to obtain the LP mode and the LP mode simultaneously. A mode interferometer based on a few-mode long period fiber grating (FM-LPFG) is used as a comb filter in the ring-cavity fiber laser. Read More

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Tunable narrowband cascaded random Raman fiber laser.

Opt Express 2021 Jul;29(14):21539-21550

Random Raman fiber lasers (RRFLs) with half-opened cavity have been used as a new platform for designing high performance, wavelength-agile laser sources in the infrared region due to their intrinsic modeless property and structural simplicity. To provide the point feedbacks for cascaded random Raman lasing at different wavelengths, wavelength-insensitive broadband reflectors are commonly used in cascaded RRFLs, resulting in the rather broad high-order random Raman lasing with several nanometers of typical spectral width. Here, we experimentally demonstrate a tunable narrowband cascaded RRFL with an air-spaced etalon assisted point reflector. Read More

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Avoidance of four-wave mixing in optical fiber bundle for coherent anti-Stokes Raman scattering endomicroscopy.

Opt Lett 2021 Jul;46(14):3356-3359

We propose and demonstrate a method of suppressing four-wave mixing (FWM) in an optical fiber bundle to realize coherent anti-Stokes Raman scattering (CARS) endomicroscopy, which is the leading candidate for a definitive diagnosis of gastrointestinal cancer. Two excitation laser beams with different wavelengths are delivered via different cores to suppress FWM and are then combined with a polarization prism and a dual-wavelength wave plate and are focused to a spot. The background emission from the optical fiber bundle was suppressed to 1/3289, and we demonstrated CARS imaging of a polystyrene bead using the proposed method. Read More

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Design and characterization of a thermally stabilized fiber Fabry-Perot etalon as a wavelength calibrator for high-precision spectroscopy.

Appl Opt 2021 Jul;60(19):D1-D8

Filtering light from a broadband source with a Fabry-Perot etalon generates comb-like peaks in the spectral domain that can serve as calibration reference for precise Doppler shift detection on astronomical spectrographs. Fiber Fabry-Perot etalons are small in size and easily aligned optically. In application, high thermal sensitivity of the fiber core material requires a highly stable temperature control system. Read More

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Current Advances in Photoactive Agents for Cancer Imaging and Therapy.

Annu Rev Biomed Eng 2021 Jul;23:29-60

Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.

Photoactive agents are promising complements for both early diagnosis and targeted treatment of cancer. The dual combination of diagnostics and therapeutics is known as theranostics. Photoactive theranostic agents are activated by a specific wavelength of light and emit another wavelength, which can be detected for imaging tumors, used to generate reactive oxygen species for ablating tumors, or both. Read More

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Dual-Mode Plasmonic Coupling-Enhanced Color Conversion of Inorganic CsPbBr Perovskite Quantum Dot Films.

ACS Appl Mater Interfaces 2021 Jul 12;13(28):32856-32864. Epub 2021 Jul 12.

Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Jiujiang Research Institute, Department of Physics / Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, Fujian 361005, China.

Plasmonic coupling has been demonstrated to be an effective manipulation strategy for emission enhancement in low-dimensional semiconductor materials. Here, dual-mode plasmonic resonances based on a metal dimer structure were proposed to simultaneously enhance the absorption under short-wavelength excitation and excitons' emission at longer wavelengths for CsPbBr perovskite quantum dots (QDs). Large-area metal nanodimer arrays with well-controlled local surface plasmon resonance were facilely fabricated by a simple method combined with metal angular deposition and nanosphere lithography. Read More

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Dissolution monitoring of diclofenac sodium and codeine phosphate tablets using fibre optic chemical sensor assisted by dual-wavelength isosbestic point spectrophotometry.

Pak J Pharm Sci 2021 Jan;34(1):111-117

College of Pharmacy, Xinjiang Medical University, Urumqi, China.

The purpose of this investigation was to establish a mathematical model for determining the dissolution of diclofenac sodium and codeine phosphate simultaneously. Based on the dual-wavelength isosbestic point spectrophotometry, the dissolution of diclofenac sodium and codeine phosphate tablets was determined using Fiber-Optic Dissolution Test (FODT) instrument capable of real-time measurement. Dissolution curves showed that the dissolution process of diclofenac sodium was similar to that of codeine phosphate. Read More

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January 2021

Epidermal nevus in blaschkoid distribution treated with dual-wavelength copper vapor laser.

Indian J Dermatol Venereol Leprol 2021 Jun 24:1-3. Epub 2021 Jun 24.

Lebedev Physical Institute of the Russian Academy of Sciences, Leninskiy Prospect, Moscow, Russian Federation.

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Treatment of congenital melanocytic nevi in the periorbital area with dual-wavelength copper vapor laser.

Indian J Dermatol Venereol Leprol 2021 Jul 7:1-3. Epub 2021 Jul 7.

Department of Methodical, National Medical Research Center of Children Health, Moscow, Russia.

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Nitrogen-doped carbon dots for dual-wavelength excitation fluorimetric assay for ratiometric determination of phosalone.

Mikrochim Acta 2021 Jul 9;188(8):247. Epub 2021 Jul 9.

Technical Center of Nanning Customs District, Nanning, 530021, China.

N-doped carbon dots (N-CDs) were fabricated in a simple procedure by hydrothermal treatment of cellobiose and urea. When excited at 235 nm or 327 nm, only one emission peak at around 420 nm has been observed. With the addition of phosalone, the excitation band at 235 nm was efficiently quenched within 1 min, while the excitation band at 327 nm showed little change. Read More

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Environmental and Nutritional Determinants of Macular Pigment in a Mexican Population.

Invest Ophthalmol Vis Sci 2021 Jul;62(9):18

Nutrition Research Centre Ireland, School of Health Science, Waterford Institute of Technology, Waterford, Ireland.

Purpose: The carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin deposit at the macula as macular pigment (MP) and provide visual benefits and protection against macular diseases. The present study investigated MP, its nutritional and environmental determinants, and its constituent carotenoids in serum from a Mexican sample, in healthy participants and with metabolic diseases. Additionally, we compared these variables with an Irish sample. Read More

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Optimal Duration of Compression Stocking Therapy after Endovenous Laser Ablation Using a 1470-nm Diode Dual-Ring Radial Laser Fiber for Great Saphenous Vein Insufficiency.

Ann Vasc Dis 2021 Jun;14(2):122-131

Department of Surgery, Saiseikai Fukuoka General Hospital, Fukuoka, Fukuoka, Japan.

To investigate the optimal duration of compression therapy after endovenous laser ablation (EVLA) using a 1470-nm diode dual-ring radial laser fiber for great saphenous vein (GSV) insufficiency. Patients undergoing EVLA of GSV for varicose vein disease were divided into two groups based on the duration of subsequent compression after the procedure: short duration group (S group; 0-2 days) and long duration group (L group; 1-4 weeks). Patient-reported outcomes (pain and quality of life [QOL]) were set as the primary outcomes, and objective findings (venous clinical severity score [VCSS], leg circumference, and duplex ultrasound [DUS] findings) were set as the secondary outcomes. Read More

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High-sensitivity and wide-temperature-range dual-mode optical thermometry under dual-wavelength excitation in a novel double perovskite tellurate oxide.

Dalton Trans 2021 Jul 6. Epub 2021 Jul 6.

School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China.

Novel double perovskite SrLaLiTeO6 (abbreviated as SLLT):Mn4+,Dy3+ phosphors synthesized using a solid-state reaction strategy exhibit distinct dual-emission of Mn4+ and Dy3+. High-sensitivity and wide-temperature-range dual-mode optical thermometry was exploited taking advantage of the diverse thermal quenching between Mn4+ and Dy3+ and the decay lifetime of Mn4+. The thermometric properties in the range of 298-673 K were investigated by utilizing the fluorescence intensity ratio (FIR) of Dy3+ (4F9/2 → 6H13/2)/Mn4+ (2Eg → 4A2g) and the Mn4+ (2Eg → 4A2g) lifetime under 351 nm and 453 nm excitation, respectively. Read More

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Cubic spline-based depth-dependent localization of mitochondria-endoplasmic reticulum contacts by three-dimensional light-sheet super-resolution microscopy.

Analyst 2021 Jul 6. Epub 2021 Jul 6.

Department of Chemistry, Graduate School, Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea and Department of Applied Chemistry and Institute of Natural Sciences, Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea.

The contact distance between mitochondria (Mito) and endoplasmic reticulum (ER) has received considerable attention owing to their crucial function in maintaining lipid and calcium homeostasis. Herein, cubic spline algorithm-based depth-dependent fluorescence-free three-dimensional light-sheet super-resolution microscopy (3D LSRM) with dual-wavelength illumination sources was investigated to study the distance of Mito-ER contacts in various live cells. To detect wavelength-dependent scattering, 12 nm gold nanoparticles (AuNPs) and 20 nm silver nanoparticles (AgNPs) as fluorescence-free nanoprobes were conjugated with Mito and ER. Read More

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Anthracene-containing complexes of boron difluoride. Dual luminescence, formation of excimers, and mechanochromism.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Jun 29;262:120114. Epub 2021 Jun 29.

Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences Department, Prosp. 100 letiya Vladivostoka, 159, Vladivostok, Russian Federation.

A comparative study of the luminescence properties and crystal structure of boron difluoride 1-(anthracen-9-yl)butane-1,3-dionate (1) and their nitrogen-containing analogs with hydrogen and methyl substituents (2 and 3) has been performed. For boron difluoride beta-diketonate (1) and beta-ketoiminate with a hydrogen substituent (2), which does not create significant steric difficulties, the luminescence of crystals is determined by that of excimers and aggregates based on them. For the compounds 1-3, mechanofluorochromism has been observed, the spectral manifestation of which is different: at grinding the crystals of 1 and 2, a hypsochromic shift of the excitation and luminescence bands occurs, whereas in the case of crystals of 3, a bathochromic shift takes place. Read More

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Comparative study of novel green UV-spectrophotometric platforms for simultaneous rapid analysis of flumethasone pivalate and clioquinol in their combined formulation.

Drug Dev Ind Pharm 2021 Jul 5:1-11. Epub 2021 Jul 5.

Faculty of Pharmacy, Analytical Chemistry Department, Zagazig University, Zagazig, Egypt.

Flumethasone pivalate (FP) and clioquinol (CL) formulation was developed as a prodigious remedy to cure the external ear inflammatory disorders. So, the current research introduces five smart and novel UV-spectrophotometric platforms relying on minimal mathematical manipulation steps for simultaneous green analysis of FP and CL with no preliminary separation in their formulation that suffered from the high difference of their ratio and severe spectral overlapping. These platforms involved dual-wavelength, first derivative ratio, Fourier self-deconvolution, area under the curve, and bivariate methods. Read More

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High-Efficiency, Dual-Band Beam Splitter Based on an All-Dielectric Quasi-Continuous Metasurface.

Materials (Basel) 2021 Jun 9;14(12). Epub 2021 Jun 9.

State Grid Information & Telecommunication Branch, Beijing 100761, China.

Metasurface-based beam splitters attracted huge interest for their superior properties compared with conventional ones made of bulk materials. The previously reported designs adopted discrete metasurfaces with the limitation of a discontinuous phase profile. In this paper, we propose a dual-band beam splitter, based on an anisotropic quasi-continuous metasurface, by exploring the optical responses under x-polarized (with an electric field parallel to the direction of the phase gradient) and y-polarized incidences. Read More

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In Vivo Assessment of Hypoxia Levels in Pancreatic Tumors Using a Dual-Modality Ultrasound/Photoacoustic Imaging System.

Micromachines (Basel) 2021 Jun 7;12(6). Epub 2021 Jun 7.

Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, No. 35, Keyan Rd., Zhunan Township, Miaoli 35053, Taiwan.

Noninvasive anatomical and functional imaging has become an essential tool to evaluate tissue oxygen saturation dynamics in preclinical or clinical studies of hypoxia. Our dual-wavelength technique for photoacoustic (PA) imaging based on the differential absorbance spectrum of oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) can quantify tissue oxygen saturation using the intrinsic contrast property. PA imaging of tissue oxygen saturation can be used to monitor tumor-related hypoxia, which is a particularly relevant functional parameter of the tumor microenvironment that has a strong influence on tumor aggressiveness. Read More

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The Investigation on Ultrafast Pulse Formation in a Tm-Ho-Codoped Mode-Locking Fiber Oscillator.

Molecules 2021 Jun 7;26(11). Epub 2021 Jun 7.

China Key Laboratory of Laser & Infrared System (Ministry of Education), Shandong Provincial Key Laboratory of Laser Technology and Application, School of Information Science and Engineering, Shandong University, Qingdao 266237, China.

We experimentally investigate the formation of various pulses from a thulium-holmium (Tm-Ho)-codoped nonlinear polarization rotation (NPR) mode-locking fiber oscillator. The ultrafast fiber oscillator can simultaneously operate in the noise-like and soliton mode-locking regimes with two different emission wavelengths located around 1947 and 2010 nm, which are believed to be induced from the laser transition of Tm and Ho ions respectively. When the noise-like pulse (NLP) and soliton pulse (SP) co-exist inside the laser oscillator, a maximum output power of 295 mW is achieved with a pulse repetition rate of 19. Read More

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High-efficiency dual-band-multiplexing three-port grating coupler on 220-nm silicon-on-insulator with 248-nm deep-UV lithography.

Opt Lett 2021 Jul;46(13):3308-3311

We experimentally demonstrate a novel, to the best of our knowledge, three-port grating coupler (TPGC) for dual-wavelength-band operation. The TPGC can couple light to/from two ports for S/C-band with polarization diversity and a third port for O-band. Such a coupling scheme could be applied in an integrated wavelength-division-multiplexing passive optical network (PON) unit, benefiting a polarization-diverse receiver for downstream S/C-band and transmitter for upstream O-band. Read More

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Experimental realization of wavelength multiplexed nonlinear upconversion in cesium atoms.

Opt Lett 2021 Jul;46(13):3119-3122

Blue-violet wavelength multiplexing offers the capability to enhance the operational capacity and efficiency in optical information processing, underwater communications, biology, and medicine. Here we present a specially designed atomic scheme of cesium for simultaneously generating two blue-violet lasers at 456 and 459 nm via four-wave-mixing (FWM)-based upconversion processes. We experimentally and theoretically show that a double-diamond-type coherent system pumped with 852 and 921 nm lasers is responsible for the efficient generation of the two blue-violet lasers. Read More

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Compact chirped-pulse amplification systems based on highly Tm-doped germanate fiber.

Opt Lett 2021 Jul;46(13):3013-3016

We report the fabrication of a dual cladding large mode area thulium-doped germanate fiber (TDGF). The fiber has a core diameter of 20 µm, a high ion concentration of 3×10/, and a hexagonal inner cladding to enhance pump absorption when cladding-pumped. Using a short fiber length, we demonstrate a compact 300 fs chirped-pulse amplification system operating at 1925 nm, investigating both core- and cladding-pumped implementations. Read More

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Smart Mathematical Manipulation of Spectral Signals: Stability Indicating, for the Estimation of Solifenacin Succinate: Anti-Muscarinic Drug, in Existence of its Acid Degradation Product.

J AOAC Int 2021 Jun 30. Epub 2021 Jun 30.

Egyptian Russian University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Badr city, Cairo, Egypt.

Background: Four rapid, smart, and easy to apply spectrophotometric methods were displayed for the estimation of Solifenacin succinate (SOL) in existence of its acid inspired degradation product.

Objective: Development of stability indicating smart, sensitive, cheap spectrophotometric methods for determination of SOL in presence of its acid degradate.

Methods: (Method A) is dual wavelength (DW) method; where, two wavelengths were selected; 262 and 289 nm were utilized to determine SOL in existence of its acid degradate. Read More

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A ratiometric fluorescent probe based on carbon dots and gold nanocluster encapsulated metal-organic framework for detection of cephalexin residues in milk.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Jun 16;262:120089. Epub 2021 Jun 16.

School of Mechanical Engineering, Yeungnam University, Gyeongsan 38541, South Korea. Electronic address:

Herein, we report a ratiometric fluorescent probe based on in situ incorporation of both Gold nanoclusters (AuNCs) and Green emitting carbon dots (gCDs) into zeolitic imidazolate framework-8 (ZIF-8) to analysis of Cephalexin (CFX). Under a single excitation wavelength of 400 nm, the sensor exhibits dual-emissions centered at 520 and 630 nm. The fluorescence of AuNCs (630 nm) is selectively quenched by CFX, whereas the fluorescence of gCDs (520 nm) remainsalmostconstant. Read More

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Phototactic Behavioral Response of the Ectoparasitoid Beetle Dastarcus helophoroides (Coleoptera: Bothrideridae): Evidence for Attraction by Near-Infrared Light.

J Econ Entomol 2021 Jun 25. Epub 2021 Jun 25.

Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration in Poyang Lake Watershed, College of Forestry, Jiangxi Agriculture University, Nanchang, China.

The ectoparasitoid beetle, Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae), has been widely used as a biological control agent for many cerambycid beetles in China, Korea, and Japan. However, much less is known about its phototactic behavior to visual stimuli. In this paper, the phototactic behavioral response of D. Read More

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Convection enhanced delivery of light responsive antigen capturing oxygen generators for chemo-phototherapy triggered adaptive immunity.

Biomaterials 2021 Jun 16;275:120974. Epub 2021 Jun 16.

Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, 117585, Singapore. Electronic address:

In recent years, combination therapy has emerged as the cornerstone of clinical practice in treating glioblastoma multiforme. However, their ability to trigger and leverage the body's adaptive immunity has rarely been studied. Tumour heterogeneity, the presence of the blood-brain barrier, and an immunosuppressive tumor microenvironment play a crucial role in the 90% local tumor recurrence post-treatment. Read More

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Fiber-based photoacoustic remote sensing microscopy and spectral-domain optical coherence tomography with a dual-function 1050-nm interrogation source.

J Biomed Opt 2021 Jun;26(6)

Univ. of Alberta, Canada.

Significance: Spectral-domain optical coherence tomography (SD-OCT) offers depth-resolved imaging of optical scattering contrast but is limited in sensitivity to optical absorption. Dual-modality imaging combined with the noncontact absorption contrast of photoacoustic remote sensing (PARS) microscopy can augment SD-OCT applications with specific molecular and functional contrasts in an all-optical, fiber-based platform.

Aim: To develop a fiber-based multimodal PARS and SD-OCT imaging system, which efficiently uses a common 1050-nm light source for SD-OCT and PARS interrogation. Read More

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Dual Ag/Co cocatalyst synergism for the highly effective photocatalytic conversion of CO by HO over Al-SrTiO.

Chem Sci 2021 Feb 24;12(13):4940-4948. Epub 2021 Feb 24.

Department of Molecular Engineering, Graduate School of Engineering, Kyoto University Kyoto 615-8510 Japan

Loading Ag and Co dual cocatalysts on Al-doped SrTiO (AgCo/Al-SrTiO) led to a significantly improved CO-formation rate and extremely high selectivity toward CO evolution (99.8%) using HO as an electron donor when irradiated with light at wavelengths above 300 nm. Furthermore, the CO-formation rate over AgCo/Al-SrTiO (52. Read More

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February 2021

Bi and Sb Codoped CsAgNaInCl Double Perovskite with Excitation-Wavelength-Dependent Dual-Emission for Anti-Counterfeiting Application.

ACS Appl Mater Interfaces 2021 Jul 23;13(26):31031-31037. Epub 2021 Jun 23.

Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, People's Republic of China.

The growing demands for optical anti-counterfeiting technology require the development of new environmentally friendly materials with single component, multimodal fluorescence and high stability. Herein, the Bi/Sb codoped CsAgNaInCl lead-free double perovskite material is reported as an efficient multimodal luminescence material with excitation-wavelength-dependent emission. When excited by 360 nm UV light, dual-emission is observed at 455 and 560 nm, which comes from the P-S transition of Sb ions and self-trapped excitons (STEs), respectively. Read More

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