4,460 results match your criteria fiber cavity

High-stability, linearly polarized mode-locking generation from a polarization-maintaining fiber oscillator around 2.8  µm.

Opt Lett 2021 Sep;46(18):4550-4553

In this Letter, a high-stability, linearly polarized mode-locked polarization-maintaining (PM) -doped fluoride fiber oscillator at ∼2.8µ is presented for the first time, to the best of our knowledge, where an InAs-based semiconductor saturable absorber mirror is used as the mode locker, and a film polarizer is employed for maintaining the linearly polarized oscillation. In the free-running state, stable linearly polarized mode-locked pulses (=44 and =446) at 2. Read More

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September 2021

Chirped dissipative solitons in driven optical resonators.

Optica 2021 Jun;8(6):861-869

Institute of Optics, University of Rochester, Rochester, New York 14627, USA.

Solitons are self-sustaining particle-like wave packets found throughout nature. Optical systems such as optical fibers and mode-locked lasers are relatively simple, are technologically important, and continue to play a major role in our understanding of the rich nonlinear dynamics of solitons. Here we present theoretical and experimental observations of a new class of optical soliton characterized by pulses with large and positive chirp in normal dispersion resonators with strong spectral filtering. Read More

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Physical-Mechanical Properties of Bamboo Fiber Composites Using Filament Winding.

Polymers (Basel) 2021 Aug 29;13(17). Epub 2021 Aug 29.

International Centre for Bamboo and Rattan, Beijing 100102, China.

In order to study the performance of the bamboo fiber composites prepared by filament winding, composites reinforced with jute fiber and glass fiber were used as control samples. The structure and mechanical properties of the composites were investigated by scanning electric microscope (SEM), tensile testing, bending testing, and dynamic mechanical analysis. The results demonstrated that the bamboo fiber composites exhibited lower density (0. Read More

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Wavelength-Tunable L-Band High Repetition Rate Erbium-Doped Fiber Laser Based on Dissipative Four-Wave Mixing.

Sensors (Basel) 2021 Sep 6;21(17). Epub 2021 Sep 6.

Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai Institute for Advanced Communication and Data Science, Shanghai University, Shanghai 200444, China.

A wavelength-tunable high repetition rate (HRR) erbium-doped fiber laser in L-band based on dissipative four-wave mixing (DFWM) mechanism is demonstrated. The cavity can generate a single-soliton train and bound-soliton train with a fixed repetition rate of ~126 GHz, which is determined by the free spectral range of the intra-cavity Lyot filter. A wide wavelength-tuning operation can also be obtained by rotating the polarization controllers. Read More

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September 2021

Anti-resonant hollow-core fiber fusion spliced to laser gain fiber for high-power beam delivery.

Opt Lett 2021 Sep;46(17):4374-4377

We present the selective excitation of the fundamental mode in an anti-resonant hollow-core fiber (ARHCF) fusion-spliced with a commercial large mode area (LMA) fiber. By designing and fabricating a single-ring ARHCF that is mode-matched to a LMA fiber and by splicing the two using a laser-based splicer, we achieve a coupling efficiency of 91.2% into the fundamental mode. Read More

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September 2021

Coupling scheme for graphene saturable absorber in a linear cavity mode-locked fiber laser.

Kuo Hua D N Wang

Opt Lett 2021 Sep;46(17):4362-4365

A saturable absorber based on a graphene layer covered single-mode fiber with inner short waveguides is proposed and demonstrated for a linear cavity Er-doped mode-locked fiber laser. A pair of short waveguides is written in the fiber by using femtosecond micromachining technology, and the propagating light is guided by one short waveguide to the cladding-air interface and interacts with the graphene layer in the form of evanescent waves before being collected back to the core by another short waveguide, and, as a result, the saturable absorption is excited. The designed saturable absorber is used in the passively mode-locked fiber laser to generate traditional soliton mode-locked pulse output with the center wavelength of 1564. Read More

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September 2021

Raman enhancement mechanism and experiments of cavity-enhanced AgNP decorated tapered fiber sensor.

Opt Lett 2021 Sep;46(17):4300-4303

A Raman sensor based on a cavity-enhanced Ag nanoparticle (AgNP) decorated tapered fiber is proposed. Its Raman enhancements are mainly caused by the localized surface plasmon resonance effect of AgNPs decorated on the tapered optical fiber surface and the further reflective laser excitation induced by the capillary-based reflective cavity. We theoretically investigate the backward Stokes power conversion efficiency and cavity enhancement factor of the sensor. Read More

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September 2021

Measuring Effects of Dietary Fiber on the Murine Oral Microbiome with Enrichment of 16S rDNA Prior to Amplicon Synthesis.

Methods Mol Biol 2021 ;2327:271-280

Department of Biology, Mercer University, Macon, GA, USA.

The oral cavity houses a diverse consortium of microorganisms corresponding to specific microbial niches within the oral cavity. The complicated nature of sample collection limits the accuracy, reproducibility, and completeness of sample collection of the dentogingival microbiome. Moreover, large variability among human oral samples introduces inexorable confounds. Read More

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January 2021

Flexible fiber-based CO laser vs monopolar cautery for resection of oral cavity lesions: A single center randomized controlled trial assessing pain and quality of life following surgery.

Laryngoscope Investig Otolaryngol 2021 Aug 10;6(4):690-698. Epub 2021 Jul 10.

Department of Surgery Head and Neck Service, Memorial Sloan Kettering Cancer Center New York New York USA.

Importance: This study reports the impact of laser surgery on quality of life in patients with oral cavity lesions.

Objective: To compare postoperative pain and quality of life in patients treated with flexible fiberoptic CO laser vs electrocautery in patients with oral cavity precancerous lesions and early stage cancers.

Design: Randomized controlled trial. Read More

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Highly precise in-plane displacement sensor based on an asymmetric fiber Fabry-Perot interferometer.

Opt Lett 2021 Aug;46(16):3945-3948

An in-plane displacement sensor based on an asymmetric extrinsic fiber Fabry-Perot interferometer (EFPI) is proposed and demonstrated. The asymmetric EFPI composed of a step-shaped external reflector and a cleaved fiber end face can be equivalent to two parallel FPIs with slightly different cavity lengths. By calculating the peak intensity difference of the two FPIs, the in-plane displacement can be demodulated with enhanced sensitivity and suppressed common mode noise. Read More

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Robust and easy-to-operate stretched-pulse mode-locked wavelength-swept laser with an all-polarization-maintaining fiber cavity for 10  MHz A-line rate optical coherence tomography.

Opt Lett 2021 Aug;46(16):3857-3860

We demonstrate robust and easy-to-operate stretched-pulse mode-locked laser (SPML) architectures using all-polarization-maintaining fiber laser cavities. Because of the polarization-maintaining construction, the laser performance is unaffected by mechanical perturbation on the cavity fibers. The lasers automatically initiate linear-in-wavenumber sweeps across 100 nm centered at 1290 nm with a 10 MHz repetition rate. Read More

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A Composite Fabry-Perot Interferometric Sensor with the Dual-Cavity Structure for Simultaneous Measurement of High Temperature and Strain.

Sensors (Basel) 2021 Jul 22;21(15). Epub 2021 Jul 22.

School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, China.

In this paper, an optical fiber composite Fabry-Perot interferometric (CFPI) sensor capable of simultaneous measurement of high temperature and strain is presented. The CFPI sensor consists of a silica-cavity intrinsic Fabry-Perot interferometer (IFPI) cascading an air-cavity extrinsic Fabry-Perot interferometer (EFPI). The IFPI is constructed at the end of the transmission single-mode fiber (SMF) by splicing a short piece of photonic crystal fiber (PCF) to SMF and then the IFPI is inserted into a quartz capillary with a reflective surface to form a single-ended sliding EFPI. Read More

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The Low Breaking Fiber Mechanism and Its Effect on the Behavior of the Melt Flow of Injection Molded Ultra-Long Glass Fiber Reinforced Polypropylene Composites.

Polymers (Basel) 2021 Jul 28;13(15). Epub 2021 Jul 28.

Department of Chemical and Materials Engineering, Tamkang University College of Engineering, New Taipei City 251301, Taiwan.

In this study, fiber breaking behavior, fiber orientation, length variation, and changes in melt flow ability of long glass fiber reinforced polypropylene (L-FRP) composites under different mold cavity geometry, melt fill path, and plasticization parameters were investigated. The matrix material used was polypropylene and the reinforcement fibers were 25 mm long. An ultra-long-fiber composite injection molding machine (with a three-stage plunger and injection mechanism design) was used with different mold cavity geometry and plasticization parameters. Read More

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Stress Concentration of Endodontically Treated Molars Restored with Transfixed Glass Fiber Post: 3D-Finite Element Analysis.

Materials (Basel) 2021 Jul 29;14(15). Epub 2021 Jul 29.

Graduate Program in Dentistry, Department of Dentistry, University of Taubaté (UNITAU), Taubaté 12020-270, Brazil.

The loss of dental structure caused by endodontic treatment is responsible for a decrease in tooth resistance, which increases susceptibility to fracture. Therefore, it is important that minimally invasive treatments be performed to preserve the dental structure and increase the resistance to fracture of endodontically treated posterior teeth. To evaluate under axial loads, using the finite element method, the stress distribution in endodontically treated molars restored with both transfixed or vertical glass fiber posts (GFP) and resin composite. Read More

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Development of a deuterium-ice extruder for inertial confinement fusion experiments on the Z Facility.

Rev Sci Instrum 2021 Jul;92(7):073505

Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.

A deuterium-ice extruder has been developed for inertial confinement fusion experiments on the Sandia National Laboratories Z Facility. The screw-driven extruder is filled via desublimation, where a slow flow of deuterium gas enters the extruder cavity and freezes to the walls without entering the liquid phase. Ice generated in this manner is optically clear, demonstrating its high uniformity. Read More

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Effectiveness of photodynamic therapy on bonding strength and failure modes of fiber-posts in c-shaped treated root canals.

Photodiagnosis Photodyn Ther 2021 Sep 30;35:102469. Epub 2021 Jul 30.

Dental Health Department, College of Applied Medical Sciences, King Saud University, P.O Box 10219, Riyadh 11433, Saudi Arabia.

Aim: The present study aimed to assess the push-out bond strength (PBS) and failure modes of fiber-posts after photodynamic therapy (PDT) and Erbium yttrium scandium gallium garnet (Er,Cr:YSGG) in c-shaped canals.

Methods: Sixty molars with c-shaped root configuration were studied. The endodontic prepared teeth specimen were equally randomized into four groups: i) photodynamic therapy (PDT); ii) Er,Cr:YSGG; iii) chlorhexidine and; iv) control group. Read More

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September 2021

Narrow-linewidth single-polarization fiber laser using non-polarization optics.

Opt Lett 2021 Aug;46(15):3769-3772

Single longitudinal mode and single polarization are basic requirements of high performance fiber lasers, while their realizations are nontrivial, owing to the long laser cavity and lack of polarization selection of ordinary optical fibers. Here, we demonstrate an all-fiber narrow-linewidth laser realized on an external high-Q fiber ring, with combined functions of single-longitude-mode selection and linewidth reduction. A single-longitude-mode laser with a high polarization extinction ratio of ∼40 and low white frequency noise at 0. Read More

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2.5  GHz harmonic mode locking from a femtosecond Yb-doped fiber laser with high fundamental repetition rate.

Opt Lett 2021 Aug;46(15):3621-3624

We experimentally demonstrated a high repetition rate harmonic mode-locked fiber laser with a high signal-to-noise ratio (SNR) and super mode suppression ratio. A novel approach using a laser with a high fundamental repetition rate and low harmonic order was presented. 2. Read More

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Mode-locked all-PM Nd-doped fiber laser near 910  nm.

Opt Lett 2021 Aug;46(15):3564-3567

We present a compact passively mode-locked fiber laser emitting near 910 nm with an all-polarization-maintaining fiber laser architecture. The ring-cavity laser configuration includes a core-pumped neodymium-doped fiber as a gain medium and a semiconductor saturable absorber mirror as a passive mode-locking element. A bandpass filter is used to suppress parasitic emission near 1. Read More

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Proposal for a Deterministic Single-Atom Source of Quasisuperradiant N-Photon Pulses.

Phys Rev Lett 2021 Jul;127(3):033602

Dodd-Walls Centre for Photonic and Quantum Technologies, New Zealand.

We propose a single-atom, cavity quantum electrodynamics system, compatible with recently demonstrated, fiber-integrated micro- and nanocavity setups, for the on-demand production of optical number-state, 0N-state, and binomial-code-state pulses. The scheme makes use of Raman transitions within an entire atomic ground-state hyperfine level and operates with laser and cavity fields detuned from the atomic transition by much more than the excited-state hyperfine splitting. This enables reduction of the dynamics to that of a simple, cavity-damped Tavis-Cummings model with the collective spin determined by the total angular momentum of the ground hyperfine level. Read More

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Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Different Core Build-up Materials: An Study.

Int J Clin Pediatr Dent 2021 Jan-Feb;14(1):51-58

Department of Pedodontics and Preventive Dentistry, Sri Guru Ram Das Institute of Dental Sciences and Research, Amritsar, Punjab, India.

The aim is to evaluate the fracture resistance of endodontically treated teeth restored with posterior direct composite (PRC) resin, bulk-fill composite resin, dual-cure composite (DCC) resin, and short fiber-reinforced composite (SFC) resin material.

Materials And Methods: Ninety sound maxillary premolar teeth were divided into 6 groups which comprised 15 teeth each. Group I was a negative control group where neither cavity preparation nor root canal treatment was done on the specimen. Read More

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Underwater In Situ Dissolved Gas Detection Based on Multi-Reflection Raman Spectroscopy.

Sensors (Basel) 2021 Jul 15;21(14). Epub 2021 Jul 15.

College of Information Science and Engineering, Ocean University of China, Qingdao 266100, China.

The detection of dissolved gases in seawater plays an important role in oceanic observations and exploration. As a potential technique for oceanic applications, Raman spectroscopy has been successfully applied in hydrothermal vents and cold seep fluids, but it has not yet been used in common seawater due to the technique's lower sensitivity. In this work, we present a highly sensitive underwater in situ Raman spectroscopy system for dissolved gas detection in common seawater. Read More

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Upper-lip laser frenectomy with a diode laser in a pediatric patient: a case report.

J Biol Regul Homeost Agents 2021 May-Jun;35(3 Suppl. 1):29-35

Department of Chemical Science and Technologies, Dentistry, University of Rome "Tor Vergata", Rome, Italy.

The case report aims to describe the parameters of performing upper labial frenectomy with the use of diode laser beams without infiltrated local anaesthesia. A 6-year-old patient was referred by the orthodontist for assessment of the upper anterior labial frenum. The dental treatment plan reported only the presence of caries on deciduous teeth and seals on the first permanent molars. Read More

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Ruptured mesenteric desmoid-type fibromatosis without emergency surgery: A rare case report.

Int J Surg Case Rep 2021 Aug 17;85:106208. Epub 2021 Jul 17.

Department of Surgery, Asahi University Hospital, 3-23, Hashimoto-cho, Gifu, Gifu 500-8523, Japan.

Introduction: Desmoid-type fibromatosis (DF) is a rare tumor that develops in the limbs, abdominal wall, and abdominal cavity. It is accounting for less than 3% of soft-tissue sarcomas and less than 0.03% of all neoplasms. Read More

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Effect of EDTA Concentrations as Irrigation Solution on Bonding of Fiber Posts into Root Canals with Universal Adhesives.

J Adhes Dent 2021 Jul;23(4):347-356

Purpose: To evaluate the effect of different concentrations of ethylene-diamine-tetra acetic acid (EDTA) on bond strength (BS) and nanoleakage (NL) of fiber posts bonded into root canals.

Materials And Methods: Seventy-two single roots were endodontically treated and divided into six groups (n = 12), according to the combination of the following factors: surface treatment (no irrigation [control], 17% EDTA, or 24% EDTA), and composite cement applied with an adhesive used in a self-etch mode (Single Bond Universal/RelyX Ultimate [SB], 3M Oral Care; Ambar Universal/Allcem [AM], FGM). After fiber post cementation, six 1-mm-thick disks were obtained for each root. Read More

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A Thorough Analysis of the Endocrown Restoration: A Literature Review.

J Contemp Dent Pract 2021 Apr 1;22(4):422-426. Epub 2021 Apr 1.

Department of Prosthodontics, National and Kapodistrian University of Athens, Athens, Greece.

Aim: The aim of this literature review is to determine whether endocrowns are a reliable alternative for endodontically treated teeth with extensive loss of tooth structure, the indications and contraindications of this restorative choice, the principles that should be followed for tooth preparation and which material is most appropriate for endocrown fabrication.

Background: Rehabilitation of endodontically treated teeth with severe coronal destruction has always been a challenge for the dental clinician. Until recently, the fabrication of a metal-ceramic or all-ceramic full-coverage crown along with a metal or glass fiber post has been the "gold standard" proving its efficacy via numerous clinical studies. Read More

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The vomeronasal organ: History, development, morphology, and functional neuroanatomy.

Handb Clin Neurol 2021 ;182:283-291

Department of Anatomy and Cell Biology, Faculty of Medicine, Medical University, Varna, Bulgaria.

The human vomeronasal organ (VNO) is an accessory olfactory organ located on the anteroinferior part of the nasal septum, 1.5-2.5cm from the nostrils. 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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Adaptive high-precision demodulation method based on vector matching and cluster-competitive particle swarm optimization for multiplexed FPIs.

Opt Express 2021 Jun;29(13):19605-19620

Multiplexed fiber optic Fabry-Perot interferometer (FPI) sensors are well known for their precision, simple construction, simpler wiring, and high sensing qualities. However, the limitations on existing demodulation methods degrade the measurement accuracy of multiplexed FPI sensors and necessitate large cavity length differences. In this paper, we propose an adaptive high-precision demodulation method based on vector matching and cluster-competitive particle swarm optimization (CCPSO), which transforms cavity length demodulation into searching for the global extreme. Read More

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Over 400 W graded-index fiber Raman laser with brightness enhancement.

Opt Express 2021 Jun;29(13):19441-19449

The power scaling on all-fiberized Raman fiber oscillator with brightness enhancement (BE) based on multimode graded-index (GRIN) fiber is demonstrated. Thanks to beam cleanup of GRIN fiber itself and single-mode selection properties of the fiber Bragg gratings inscribed in the center of GRIN fiber, the efficient BE is realized. For the laser cavity with single OC FBG, continuous-wave power of 334 W with an M value of 2. Read More

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