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Dai M, Wang C, Qiang B, Jin Y, Ye M, Wang F, Sun F, Zhang X, Luo Y, Wang QJ. Long-wave infrared photothermoelectric detectors with ultrahigh polarization sensitivity. Nat Commun 2023; 14:3421. [PMID: 37296149 DOI: 10.1038/s41467-023-39071-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/22/2023] [Indexed: 06/12/2023] Open
Abstract
Filter-free miniaturized polarization-sensitive photodetectors have important applications in the next-generation on-chip polarimeters. However, their polarization sensitivity is thus far limited by the intrinsic low diattenuation and inefficient photon-to-electron conversion. Here, we implement experimentally a miniaturized detector based on one-dimensional tellurium nanoribbon, which can significantly improve the photothermoelectric responses by translating the polarization-sensitive absorption into a large temperature gradient together with the finite-size effect of a perfect plasmonic absorber. Our devices exhibit a zero-bias responsivity of 410 V/W and an ultrahigh polarization ratio (2.5 × 104), as well as a peak polarization angle sensitivity of 7.10 V/W•degree, which is one order of magnitude higher than those reported in the literature. Full linear polarimetry detection is also achieved with the proposed device in a simple geometrical configuration. Polarization-coded communication and optical strain measurement are demonstrated showing the great potential of the proposed devices. Our work presents a feasible solution for miniaturized room-temperature infrared photodetectors with ultrahigh polarization sensitivity.
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Affiliation(s)
- Mingjin Dai
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Chongwu Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Bo Qiang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Yuhao Jin
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Ming Ye
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Fakun Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Fangyuan Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Xuran Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Yu Luo
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
| | - Qi Jie Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.
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Xie Y, Cai D, Pan J, Zhou N, Gao Y, Jin Y, Jiang X, Qiu J, Wang P, Guo X, Tong L. Batch Fabrication of High-Quality Infrared Chalcogenide Microsphere Resonators. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100140. [PMID: 33811462 DOI: 10.1002/smll.202100140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/09/2021] [Indexed: 06/12/2023]
Abstract
Optical microsphere resonators working in the near- and mid-infrared regions are highly required for a variety of applications, such as optical sensors, filters, modulators, and microlasers. Here, a simple and low-cost approach is reported for batch fabrication of high-quality chalcogenide glass (ChG) microsphere resonators by melting high-purity ChG powders in an oil environment. Q factors as high as 1.2 × 106 (7.4 × 105 ) are observed in As2 S3 (As2 Se3 ) microspheres (≈30 µm in diameter) around 1550-nm wavelength. Smaller microspheres with sizes around 10 µm also show excellent resonant responses (Q ≈ 2.5 × 105 ). Based on the mode splitting of an azimuthal mode in a microsphere resonator, eccentricities as low as ≈0.13% (≈0.17%) for As2 S3 (As2 Se3 ) microspheres are measured. Moreover, by coupling ChG microspheres with a biconical As2 S3 fiber taper, Q factors of ≈1.7 × 104 (≈1.6 × 104 ) are obtained in As2 S3 (As2 Se3 ) microspheres in the mid-infrared region (around 4.5 µm). The high-quality ChG microspheres demonstrated here are highly attractive for near- and mid-infrared optics, including optical sensing, optical nonlinearity, cavity quantum electrodynamics, microlasers, nanofocusing, and microscopic imaging.
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Affiliation(s)
- Yu Xie
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Dawei Cai
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jing Pan
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Ning Zhou
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yixiao Gao
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yingying Jin
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaoshun Jiang
- National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China
| | - Jianrong Qiu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Pan Wang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xin Guo
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Limin Tong
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, China
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Rocha AM, Machado AI, Almeida T, Vieira J, Facão M. Analysis of Long Period Gratings Inscribed by CO 2 Laser Irradiation and Estimation of the Refractive Index Modulation. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20226409. [PMID: 33182589 PMCID: PMC7697559 DOI: 10.3390/s20226409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/04/2020] [Accepted: 11/08/2020] [Indexed: 06/11/2023]
Abstract
Long period gratings (LPGs) inscribed in single mode fibers (SMFs) using CO2 laser irradiation were modelled numerically using the coupled mode method. The model considers the specifications of the inscription technique, such as the shape of the refractive index modulation that mimics the circularly symmetric point-to-point laser irradiation profile. A simple expression for predicting the resonant wavelength was obtained assuming a two-mode coupling model. However, to explain the spectra of the experimental LPGs, it was necessary to assume a reasonably high refractive index change and a multimode coupling model. Furthermore, using the developed model and a genetic algorithm to fit experimental resonances to simulated ones, we were able to estimate the maximum refractive index change, obtaining a value of 2.2 × 10-3, confirming the high refractive index change. The proposed model also predicts a second order resonance for this high value of refractive index change that was confirmed experimentally. Hence, with this model, we found some significant differences in the LPGs behavior when compared with conventional ones, namely, the emergence of coupling between different cladding modes and the competition of first and second order resonances which change the LPG transmission spectrum.
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Affiliation(s)
- Ana M. Rocha
- Instituto de Telecomunicações and University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (A.I.M.); (T.A.); (J.V.)
| | - Ana I. Machado
- Instituto de Telecomunicações and University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (A.I.M.); (T.A.); (J.V.)
- Department of Physics and I3N, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal;
| | - Telmo Almeida
- Instituto de Telecomunicações and University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (A.I.M.); (T.A.); (J.V.)
| | - Joana Vieira
- Instituto de Telecomunicações and University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (A.I.M.); (T.A.); (J.V.)
| | - Margarida Facão
- Department of Physics and I3N, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal;
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Observing the Viscous Relaxation Process of Silica Optical Fiber at ~1000 °C Using Regenerated Fiber Bragg Grating. SENSORS 2019; 19:s19102293. [PMID: 31109014 PMCID: PMC6567008 DOI: 10.3390/s19102293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/06/2019] [Accepted: 05/13/2019] [Indexed: 11/17/2022]
Abstract
A regenerated fiber Bragg grating (RFBG) in silica fiber was used to observe the viscous relaxation process of the host silica fiber at high temperatures of around 1000 °C. Two factors, preannealing time and loaded tension, which affect viscous relaxation, were observed. When an RFBG is stretched after a longer preannealing, the measured viscosity of the optical fiber was observed to reach equilibrium faster, which means that preannealing accelerates viscous relaxation. A similar acceleration phenomenon was also observed when a larger load was applied to stretch the optical fiber, although the acceleration effect of loaded tension was not as strong as in the preannealing case. The results play an active role in establishing effective optical-fiber devices for application in high-temperature environments.
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Effect of Gamma-Ray Irradiation on the Growth of Au Nano-Particles Embedded in the Germano-Silicate Glass Cladding of the Silica Glass Fiber and its Surface Plasmon Resonance Response. SENSORS 2019; 19:s19071666. [PMID: 30965567 PMCID: PMC6480348 DOI: 10.3390/s19071666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/01/2019] [Accepted: 04/06/2019] [Indexed: 01/12/2023]
Abstract
The effect of γ-ray irradiation on the surface plasmon resonance (SPR) sensing capability of refractive index (n = 1.418–1.448) of the silica glass optical fiber comprised of germano-silicate glass cladding embedded with Au nano-particles (NPs) was investigated. As the γ-ray irradiation increased from 1 h to 3 h with the dose rate of 1190 Gy/h, the morphology of the Au NPs and the SPR spectrum were found to change. The average diameter of Au NPs increased with the aspect ratio from 1 to 2, and the nano-particles became grown to the clusters. The SPR band wavelength shifted towards a longer wavelength with the increase of total dose of γ-ray irradiation regardless of the corresponding refractive indices. The SPR sensitivities (wavelength/refractive index unit, nm/RIU) also increased from 407 nm/RIU to 3553 nm/RIU, 1483 nm/RIU, and 2335 nm/RIU after the γ-ray irradiation at a total dose of 1190 Gy, 2380 Gy, and 3570 Gy, respectively.
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6
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Li Z, Liu S, Bai Z, Fu C, Zhang Y, Sun Z, Liu X, Wang Y. Residual-stress-induced helical long period fiber gratings for sensing applications. OPTICS EXPRESS 2018; 26:24114-24123. [PMID: 30184903 DOI: 10.1364/oe.26.024114] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a high-efficiency grating fabrication system, which can be used to inscribe a high-quality helical long period fiber grating (HLPFG) on single-mode fiber by means of hydrogen-oxygen flame. Such the HLPFG can be produced in enormous quantities with a uniform grating parameters and good reproducibility of grating inscription. Possible mechanisms for refractive index modulation in the HLPFG can be attributed to residual stress concentration by solidifying the periodic twisting stress under a fused status of optical fiber. Moreover, the HLPFG exhibits an excellence performance of high temperature sensing with a high sensitivity of ~132.8 pm/°C and a measuring range from room temperature to 900 °C. Comparing to the traditional LPFG fabricated by CO2 laser or arc discharge technique, the HLPFG has a low the bending and tensile strain sensitivity of 1.94 nm/(1/m) and 1.41 pm/με, respectively. So the proposed HLPFG could have a great potential in special applications as optical high-temperature sensors.
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7
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Wang Q, Liu Y, Zhang L, Wang T. Fabrication of asymmetric long-period gratings in polarization-maintaining fiber with a CO 2 laser. APPLIED OPTICS 2017; 56:4325-4329. [PMID: 29047856 DOI: 10.1364/ao.56.004325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We propose the fabrication of the long-period fiber gratings (LPFGs) in a panda polarization-maintaining fiber (PMF) using a two-step CO2 laser writing method. The first laser irradiation was aligned along one of the axes of the PMF and the grating with high contrast can be written after several laser scannings. The second irradiation was performed by rotating the PMF so that the other axis of the fiber aligns toward the laser exposure. New transmission dips can be observed when the first irradiation is along the slow axis and the second one is along the fast axis of the PMF. The stress relaxation effect of the stress-applying parts due to the laser heating was investigated theoretically and experimentally, which is believed to be dominant for the fabrication of the LPFGs in the PMFs by a CO2 laser.
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8
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Jenkins MH, Gaylord TK. Three-dimensional quantitative phase imaging via tomographic deconvolution phase microscopy. APPLIED OPTICS 2015; 54:9213-27. [PMID: 26560576 DOI: 10.1364/ao.54.009213] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The field of three-dimensional quantitative phase imaging (3D QPI) is expanding rapidly with applications in biological, medical, and industrial research, development, diagnostics, and metrology. Much of this research has centered on developing optical diffraction tomography (ODT) for biomedical applications. In addition to technical difficulties associated with coherent noise, ODT is not congruous with optical microscopy utilizing partially coherent light, which is used in most biomedical laboratories. Thus, ODT solutions have, for the most part, been limited to customized optomechanical systems which would be relatively expensive to implement on a wide scale. In the present work, a new phase reconstruction method, called tomographic deconvolution phase microscopy (TDPM), is described which makes use of commercial microscopy hardware in realizing 3D QPI. TDPM is analogous to methods used in deconvolution microscopy which improve spatial resolution and 3D-localization accuracy of fluorescence micrographs by combining multiple through-focal scans which are deconvolved by the system point spread function. TDPM is based on the 3D weak object transfer function theory which is shown here to be capable of imaging "nonweak" phase objects with large phase excursions. TDPM requires no phase unwrapping and recovers the entire object spectrum via object rotation, mitigating the need to fill in the "missing cone" of spatial frequencies algorithmically as in limited-angle ODT. In the present work, TDPM is demonstrated using optical fibers, including single-mode, polarization-maintaining, and photonic-crystal fibers as well as an azimuthally varying CO2-laser-induced long-period fiber grating period as test phase objects.
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9
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Lai MH, Gunawardena DS, Lim KS, Yang HZ, Ahmad H. Observation of grating regeneration by direct CO(2) laser annealing. OPTICS EXPRESS 2015; 23:452-463. [PMID: 25835690 DOI: 10.1364/oe.23.000452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this work, we have demonstrated for the first time grating regeneration in hydrogenated fibers by direct CO(2) laser annealing. During the annealing process, the center wavelength redshifts as the intensity of the focused CO(2) laser on the grating is elevated. The reflectivity of the grating begins to decay as the temperature induced in the grating approaches the erasure temperature. The grating is completely erased and regenerated afterwards. The observed spectral results have provided the proof of occurrence of dehydroxylation and stress relaxation in the fiber core during the annealing process. Regenerated gratings with low loss, good temperature sensitivities and sustainability have been successfully developed by this technique.
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10
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Tian F, Sukhishvili S, Du H. Photonic Crystal Fiber as a Lab-in-Fiber Optofluidic Platform. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/978-3-319-06998-2_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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11
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Lim KS, Yang HZ, Chong WY, Cheong YK, Lim CH, Ali NM, Ahmad H. Axial contraction in etched optical fiber due to internal stress reduction. OPTICS EXPRESS 2013; 21:2551-2562. [PMID: 23481713 DOI: 10.1364/oe.21.002551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
When an optical fiber is dipped in an etching solution, the internal stress profile in the fiber varies with the fiber diameter. We observed a physical contraction as much as 0.2% in the fiber axial dimension when the fiber was reduced from its original diameter to ~6 µm through analysis using high resolution microscope images of the grating period of an etched FBG at different fiber diameters. This axial contraction is related to the varying axial stress profile in the fiber when the fiber diameter is reduced. On top of that, the refractive index of fiber core increases with reducing fiber diameter due to stress-optic effect. The calculated index increment is as much as 1.8 × 10(-3) at the center of fiber core after the diameter is reduced down to ~6 µm. In comparison with the conventional model that assumes constant grating period and neglects the variation in stress-induced index change in fiber core, our proposed model indicates a discrepancy as much as 3nm in Bragg wavelength at a fiber diameter of ~6 µm.
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Affiliation(s)
- Kok-Sing Lim
- Photonics Research Centre, Dept. of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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12
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Tian F, Kanka J, Sukhishvili SA, Du H. Photonic crystal fiber for layer-by-layer assembly and measurements of polyelectrolyte thin films. OPTICS LETTERS 2012; 37:4299-4301. [PMID: 23073443 DOI: 10.1364/ol.37.004299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The cladding air channels of an endlessly single-mode photonic crystal fiber (PCF) and the high-index sensitivity of its long-period gratings (LPG) inscribed by CO(2) laser have been exploited to deposit poly(vinyl pyrrolidone) (PVPON)/poly(methacrylic acid) (PMAA) polyelectrolyte thin films via layer-by-layer assembly (LbL) and to measure the deposition process. We show that LbL can be controllably carried out within the axially aligned air channels. PCF-LPG is highly sensitive to the LbL process as reflected by ~1.625 nm shift in the resonance wavelength per polyelectrolyte layer incorporated. PCF-LPG is also very robust for in situ monitoring of the release of PVPON from cross-linked polyelectrolytes, which results in the formation of pH-responsive PMAA hydrogel. PCF-LPG containing the hydrogel exhibits well-behaved response to changes in solution pH over 2 to 7.5. We demonstrate that PCF-LPG is 2 orders of magnitude more sensitive than its traditional all-solid counterpart through parallel investigation.
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Affiliation(s)
- Fei Tian
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
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13
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Tian F, Kanka J, Du H. Long-period grating and its cascaded counterpart in photonic crystal fiber for gas phase measurement. OPTICS EXPRESS 2012; 20:20951-20961. [PMID: 23037218 DOI: 10.1364/oe.20.020951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Regular and cascaded long period gratings (LPG, C-LPG) of periods ranging from 460 to 590 μm were inscribed in an endlessly single mode photonic crystal fiber (PCF) using CO(2) laser for sensing measurements of helium, argon and acetylene. High index sensitivities in excess of 1700 nm/RIU were achieved in both grating schemes with a period of 460 μm. The sharp interference fringes in the transmission spectrum of C-PCF-LPG afforded not only greatly enhanced sensing resolution, but also accuracy when the phase-shift of the fringe pattern is determined through spectral processing. Comparative numerical and experimental studies indicated LP(01) to LP(03) mode coupling as the principal coupling step for both PCF-LPG and C-PCF-LPG with emergence of multi-mode coupling at shorter grating periods or longer resonance wavelengths.
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Affiliation(s)
- Fei Tian
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
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Hutsel MR, Gaylord TK. Residual-stress relaxation and densification in CO2-laser-induced long-period fiber gratings. APPLIED OPTICS 2012; 51:6179-6187. [PMID: 22945166 DOI: 10.1364/ao.51.006179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 07/19/2012] [Indexed: 06/01/2023]
Abstract
The first concurrent measurements of the three-dimensional refractive-index and residual-stress distributions in a CO(2)-laser-irradiated fiber are presented. A Corning SMF-28 fiber was exposed from one side to focused pulses with durations of 100-500 ms. The cross-sectional form of the index modulation is asymmetric with changes concentrated on the side of the fiber facing the exposure. The longitudinal form is Gaussian-like with a wide top and extends approximately 100 μm from the center of the exposure. Relaxation of frozen-in viscoelasticity results in a maximum index modulation of 5×10(-4) on the side of the fiber facing the exposure with mechanical stress relaxation contributing changes of less than 1×10(-4).
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Affiliation(s)
- Michael R Hutsel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA.
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15
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Hutsel MR, Gaylord TK. Concurrent three-dimensional characterization of the refractive-index and residual-stress distributions in optical fibers. APPLIED OPTICS 2012; 51:5442-5452. [PMID: 22859034 DOI: 10.1364/ao.51.005442] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 06/27/2012] [Indexed: 06/01/2023]
Abstract
A three-dimensional index-stress distribution (3DISD) measurement method for determining concurrently the refractive-index distributions (RIDs) and residual-stress distributions (RSDs) in optical fibers is presented. The method combines the quantitative-phase microscopy technique, the Brace-Köhler compensator technique, and computed tomography principles. These techniques are implemented on a common apparatus to enable concurrent characterization of the RID and the RSD. Measurements are performed on Corning SMF-28 fiber in an unperturbed section and in a section exposed to CO(2) laser radiation. The concurrent measurements allow for the first accurate comparison of the collocated RID and RSD. The resolutions of the refractive index and stress are estimated to be 2.34×10(-5) and 0.35 MPa, respectively.
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Affiliation(s)
- Michael R Hutsel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA
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16
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Liu X, Zhan L, Luo S, Gu Z, Liu J, Shen Q. Spectrum evolution of cascaded mismatching long-period fiber gratings. APPLIED OPTICS 2012; 51:1367-1374. [PMID: 22441484 DOI: 10.1364/ao.51.001367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/08/2011] [Indexed: 05/31/2023]
Abstract
Two identical long-period fiber gratings (LPFGs) are difficult to produce in practice, notably for CO(2)-laser or arc-discharge induced LPFGs. So it is meaningful to study the spectrum evolution of cascaded LPFGs with some deviation, named "mismatching" LPFGs. Theory and experiment demonstrate that the upper envelope of the fringe pattern is intrinsically curved but less dramatically than the lower envelope. Bending the grating pair to introduce proper cladding-mode loss can improve the contrast of the fringe pattern at a desired wavelength, which indicates that cascaded mismatching LPFGs can be used as high-quality comb filters or fiber sensors.
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Affiliation(s)
- Xuesong Liu
- Department of Physics, Key Laboratory for Laser Plasmas (Ministry of Education), State Key Lab of Advanced Optical Communication Systems and Networks, Shanghai Jiao Tong University, Shanghai, 200240, China
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Tian F, He Z, Du H. Numerical and experimental investigation of long-period gratings in photonic crystal fiber for refractive index sensing of gas media. OPTICS LETTERS 2012; 37:380-382. [PMID: 22297359 DOI: 10.1364/ol.37.000380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have used the finite-difference frequency-domain (FDFD) method to simulate the core mode to cladding mode couplings in long-period gratings (LPGs) in photonic crystal fiber (PCF). Four sets of LPG-PCF have been fabricated with respective periodicities of 590, 540, 515, and 490 μm, resulting in corresponding resonance wavelengths (RWs) of 1241, 1399, 1494, and 1579 nm. We show both theoretically and experimentally that the longer the RW, the more sensitive the LPG-PCF is to the index change in Ar. We demonstrate a robust sensitivity of 517 nm per refractive index unit using the LPG-PCF at 1579 nm RW.
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Affiliation(s)
- Fei Tian
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
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18
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Smedskjaer MM, Saxton SA, Ellison AJ, Mauro JC. Photoelastic response of alkaline earth aluminosilicate glasses. OPTICS LETTERS 2012; 37:293-295. [PMID: 22297330 DOI: 10.1364/ol.37.000293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Understanding the structural origins of the photoelastic response in oxide glasses is important for discovering new families of zero-stress optic glasses and for developing a predictive physical model. In this Letter, we have investigated the composition dependence of the stress optic coefficient C of 32 sodium aluminosilicate glasses with different types of alkaline earth oxides (MgO, CaO, SrO, and BaO). We find that most of the composition dependence of the stress optic response can be captured by a linear regression model and that the individual contributions from the alkaline earths to C depend on the alkaline earth-oxygen bond metallicity. High bond metallicity is required to allow bonds to be distorted along both the bonding direction and perpendicular to it. These findings are valuable for understanding the photoelastic response of oxide glasses.
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Affiliation(s)
- Morten M Smedskjaer
- Science and Technology Division, Corning Incorporated, Corning, New York 14831, USA
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Wu Z, Wang Z, Liu YG, Han T, Li S, Wei H. Mechanism and characteristics of long period fiber gratings in simplified hollow-core photonic crystal fibers. OPTICS EXPRESS 2011; 19:17344-17349. [PMID: 21935098 DOI: 10.1364/oe.19.017344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We demonstrate the fabrication of high-quality LPFGs in simplified hollow-core photonic crystal fibers, composed of a hollow hexagonal core and six crown-like air holes, using CO2-laser-irradiation method. Theoretical and experimental investigations indicate that the LPFGs are originated from the strong mode-coupling between the LP01 and LP11 core modes. And a dominant physical mechanism for the mode-coupling is experimentally confirmed to be the periodic microbends rather than the deformations of the cross-section or other common factors. In addition, the LPFGs are highly sensitive to strain and nearly insensitive to temperature, and are promising candidates for gas sensors and nonlinear optical devices.
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Affiliation(s)
- Zhifang Wu
- Key Laboratory of Optical Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin, China
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Tai B, Wang Z, Liu Y, Xu J, Liu B, Wei H, Tong W. High order resonances between core mode and cladding supermodes in long period fiber gratings inscribed in photonic bandgap fibers. OPTICS EXPRESS 2010; 18:15361-15370. [PMID: 20720913 DOI: 10.1364/oe.18.015361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
High order resonances between fundamental core mode and cladding LP(01) supermodes are demonstrated in long period fiber gratings (LPFGs) inscribed in all-solid photonic bandgap fibers for the first time to our knowledge. The resonance wavelengths of the LPFGs calculated by way of photonic bandgap theory agree with the experimental results. The temperature responses of these resonance peaks have been theoretically and experimentally investigated. In addition, the mechanism of LPFG formation has been researched deeply through coupled-mode theory (CMT) and the cutback experiments.
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Affiliation(s)
- Boyin Tai
- Key laboratory of Opto-electronic Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin, 300071 China
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Hutsel MR, Ingle R, Gaylord TK. Accurate cross-sectional stress profiling of optical fibers. APPLIED OPTICS 2009; 48:4985-4995. [PMID: 19745862 DOI: 10.1364/ao.48.004985] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel technique for determining two-dimensional, cross-sectional stress distributions in optical fibers and fiber-based devices is presented. Use of the Brace-Köhler compensator technique and a polarization microscope for the measurement of retardation due to stress-induced birefringence is described, along with the tomographic reconstruction process for the determination of stress. Measurements are performed on Corning SMF-28 fiber in an unperturbed section, a section near a cleaved end-face, and a section exposed to CO2 laser radiation. Cross-sectional stress distributions are presented. Stress relaxation is quantified in the cleaved fiber and the fiber exposed to CO2 laser radiation.
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Affiliation(s)
- Michael R Hutsel
- School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive, N.W., Atlanta, Georgia 30332-0250, USA.
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Li Y, Wei T, Montoya JA, Saini SV, Lan X, Tang X, Dong J, Xiao H. Measurement of CO2-laser-irradiation-induced refractive index modulation in single-mode fiber toward long-period fiber grating design and fabrication. APPLIED OPTICS 2008; 47:5296-5304. [PMID: 18846167 DOI: 10.1364/ao.47.005296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report a new method to measure the CO(2)-laser-irradiation-induced refractive index modulation in the core of a single-mode optical fiber for the purpose of design and fabrication of long-period fiber gratings (LPFGs) without applying tension. Using an optical fiber Fabry-Perot interferometer, the laser-induced axial refractive index perturbation was measured. We found that the CO(2)-laser-irradiation-induced refractive index change in the fiber core had a negative value and that the magnitude was a sensitive function of the laser exposure time following almost a linear relation. Under the assumption of a Gaussian-shaped refractive index modulation profile and based on the first two terms of Fourier series approximation, the measured refractive index perturbations were used to simulate the LPFG transmission spectra. LPFGs with the same laser exposure parameters were fabricated without applying tension, and their spectra were compared with those obtained by simulations.
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Affiliation(s)
- Yanjun Li
- Department of Electrical and Computer Engineering, Missouri University of Science and Technology, 1870 Miner Circle, Rolla, Missouri 65409-0040, USA
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Liu Y, Chiang KS. CO(2) laser writing of long-period fiber gratings in optical fibers under tension. OPTICS LETTERS 2008; 33:1933-1935. [PMID: 18758569 DOI: 10.1364/ol.33.001933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate experimentally that the efficiency of writing a long-period fiber grating in a single-mode fiber by CO(2) laser pulses increases significantly with the axial stress applied along the fiber. We attribute the enhancement in writing efficiency to the generation of nonuniform inelastic frozen-in strains across the fiber under tension by CO(2) laser heating. Controlling the axial stress distribution along a fiber during the CO(2) laser writing process thus provides an additional degree of freedom for control of the grating characteristics.
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Affiliation(s)
- Yunqi Liu
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong.
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Wang Y, Wang DN, Jin W, Rao Y. Asymmetric transverse-load characteristics and polarization dependence of long-period fiber gratings written by a focused CO(2) laser. APPLIED OPTICS 2007; 46:3079-86. [PMID: 17514259 DOI: 10.1364/ao.46.003079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Asymmetric transverse-load characteristics and the polarization dependence of long-period fiber gratings (LPFGs) written by high-frequency CO(2) laser pulses are investigated in detail. It is demonstrated that the resonant wavelength is dependent on the direction of the applied force and on the polarization state of the input light; however, the coupling strength is independent of these parameters. When a transverse load is applied along different orientations of the LPFG, the resonant wavelength may be shifted toward the longer wavelength, the shorter wavelength, or hardly shifted, whereas the absolute value of peak transmission attenuation is linearly decreased with an increase of the applied transverse load, with almost no sensitivity to the load direction. These unique transverse-load characteristics and the polarization dependence are due to the load-induced birefringence that leads to the rotation of optical principal axes in the LPFG.
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Affiliation(s)
- Yiping Wang
- Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
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Recording of long-period gratings in special single-mode fibers by a CO2 laser. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2006. [DOI: 10.1016/j.msec.2005.10.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Montarou CC, Gaylord TK, Bachim BL, Dachevski AI, Agarwal A. Two-wave-plate compensator method for full-field retardation measurements. APPLIED OPTICS 2006; 45:271-80. [PMID: 16422157 DOI: 10.1364/ao.45.000271] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The two-wave-plate compensator (TWC) method is expanded for full-field retardation measurements by use of a polarization microscope. The sample image is projected onto a CCD camera connected to a computer, allowing the retardation to be measured at all pixels. The retardation accuracy of this implementation of the TWC is evaluated to be 0.06 nm. The method is applied to polarization-maintaining fibers and long-period fiber gratings. The measured retardation is in good agreement with the crossed-polarizer images of the fibers. The method achieves a spatial resolution of 0.45 microm and a retardation resolution of 0.07 nm. The full-field TWC method can thus be a useful tool for characterizing and monitoring the fabrication of optical devices.
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Affiliation(s)
- Carole C Montarou
- School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250, USA
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Dragomir N, Baxter G, Roberts A. Phase-sensitive imaging techniques applied to optical fibre characterisation. ACTA ACUST UNITED AC 2006. [DOI: 10.1049/ip-opt:20050105] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Grubsky V, Feinberg J. Rewritable densification gratings in boron-doped fibers. OPTICS LETTERS 2005; 30:1279-81. [PMID: 15981506 DOI: 10.1364/ol.30.001279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We show that the strength of long-period gratings recorded in boron-doped fibers by CO2 radiation can be significantly enhanced by a uniform pre-exposure by the same laser. The resultant gratings could be erased by a similar uniform exposure and then recorded again multiple times with no loss of fiber sensitivity. We suggest that such gratings are formed by reversible densification of the fiber core. These densification gratings have higher thermal stability than gratings written with ultraviolet light.
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Affiliation(s)
- Victor Grubsky
- Department of Physics, University of Southern California, Los Angeles, California 90089, USA.
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Montarou CC, Gaylord TK. Two-wave-plate compensator method for single-point retardation measurements. APPLIED OPTICS 2004; 43:6580-6595. [PMID: 15646778 DOI: 10.1364/ao.43.006580] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The two-wave-plate compensator (TWC) technique is introduced for single-point retardation measurements. The TWC method uses a known wave plate together with a wave plate of unknown retardation and produces a linearly polarized output that allows a null of intensity to be detected. The TWC method is compared both theoretically and experimentally with the existing Brace-Köhler and Sénarmont methods. The resolution of the TWC is shown to be 0.02 nm. TWC enables the measurement of a sample retardation with as little as 0.13% error and thus is more accurate than either the Brace-Kohler or the Sénarmont method.
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Affiliation(s)
- Carole C Montarou
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250, USA
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Zhu Y, Shum P, Bay HW, Chen X, Tan CH, Lu C. Wide-passband, temperature-insensitive, and compact pi-phase-shifted long-period gratings in endlessly single-mode photonic crystal fiber. OPTICS LETTERS 2004; 29:2608-2610. [PMID: 15552660 DOI: 10.1364/ol.29.002608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We demonstrate what is believed to be the first fabrication of a wide-passband, temperature-insensitive, and compact spectral filter based on a pi-phase-shifted long-period grating in an endless single-mode photonic crystal fiber. By introducing a pi-phase shift in the middle of a 12-period long-period grating, two symmetrical rejection bands at wavelengths of 1252.65 and 1418.7 nm are obtained with isolation higher than 18 dB and a passband bandwidth of 84.15 nm. The pi-phase-shifted long-period gratings are inscribed by the relaxation of mechanical stress with the focused pulses of a CO2 laser and a point-by-point technique without geometric deformation. The length of the spectral filter is approximately 6.6 mm with a sensitivity of 8 pm/ degrees C at a medium temperature range of 23-190 degrees C.
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Affiliation(s)
- Yinian Zhu
- Network Technology Research Center, Nanyang Technological University, 50 Nanyang Drive, Research TechnoPlaza, Singapore 637553.
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Park Y, Choi S, Paek UC, Oh K, Kim DY. Measurement method for profiling the residual stress of an optical fiber: detailed analysis of off-focusing and beam-deflection effects. APPLIED OPTICS 2003; 42:1182-1190. [PMID: 12638875 DOI: 10.1364/ao.42.001182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The effects of off-focusing and beam deflection on polarimetric stress measurements of optical fibers are investigated. A simple method for reducing the distortion of the phase retardation caused by unwanted beam deflections in residual stress measurement is introduced. The method is examined numerically by ray-tracing techniques and experimentally by use of hollow silica fibers into which various index-matching liquids have been inserted. An autofocusing technique is introduced. The error in stress measurement reproducibility was determined to be less than 4%. We tested the absolute error in measured stress by applying incremental external tension and determined that it is less than 0.464 MPa.
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Affiliation(s)
- Yongwoo Park
- Basic Research Laboratory, Electronics and Telecommunications Research Institute, 161 Gajeong-dong, Yuseong-gu, Daejeon 305-350, Republic of Korea.
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Kim BH, Ahn TJ, Kim DY, Lee BH, Chung Y, Paek UC, Han WT. Effect of CO2 laser irradiation on the refractive-index change in optical fibers. APPLIED OPTICS 2002; 41:3809-3815. [PMID: 12099587 DOI: 10.1364/ao.41.003809] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of CO2 laser irradiation on the refractive-index change in optical fibers is investigated by measuring the interference fringe shift formed by a long-period fiber grating pair. The refractive-index decrease on CO2 laser irradiation was due to relaxation of the residual stress, which was formed in optical fibers during the drawing process, and the refractive-index decrease was found to increase linearly with the drawing force. The effect of the CO2 laser output power on residual-stress relaxation, and fiber elongation was also studied.
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Affiliation(s)
- Bok Hyeon Kim
- Department of Information and Communications, Kwangju Institute of Science and Technology, Gwangju, Korea
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Kim BH, Park Y, Kim DY, Paek UC, Han WT. Observation and analysis of residual stress development resulting from OH impurity in optical fibers. OPTICS LETTERS 2002; 27:806-808. [PMID: 18007934 DOI: 10.1364/ol.27.000806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report experimental results on the development of residual stress due to OH impurity in optical fibers. The effect of OH impurity on residual stress is demonstrated by direct residual stress measurement. The residual stress at the outer-cladding/jacketing-tube boundary of the fiber drawn at 3.48 N was found to be -61 MPa . The residual compressive stress is attributed to the viscosity decrease induced by a significant OH impurity at the boundary, as measured by a Fourier transform infrared microscope.
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