• Title/Summary/Keyword: fiber grating fabrication

Search Result 52, Processing Time 0.021 seconds

Residual Strain Characteristics of Nickel-coated FBG Sensors (니켈이 코팅된 FBG 센서의 잔류 변형률 특성)

  • Cho, Won-Jae;Hwang, A-Reum;Kim, Sang-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.41 no.7
    • /
    • pp.613-620
    • /
    • 2017
  • A metal-coated FBG (fiber Bragg grating) sensor has a memory effect, which can recall the maximum strains experienced by the structure. In this study, a nickel-coated FBG sensor was fabricated through electroless (i.e., chemical plating) and electroplating. A thickness of approximately $43{\mu}m$ of a nickel layer was achieved. Then, we conducted cyclic loading tests for the fabricated nickel-coated FBG sensors to verify their capability to produce residual strains. The results revealed that the residual strain induced by the nickel coating linearly increased with an increase in the maximum strain experienced by the sensor. Therefore, we verified that a nickel-coated FBG sensor has a memory effect. The fabrication methods and the results of the cycle loading test will provide basic information and guidelines in the design of a nickel-coated FBG sensor when it is applied in the development of structural health monitoring techniques.

Fabrication of tunable all-fiber feedback laser and its application (파장가변이 가능한 완전 광섬유형 궤환 레이저 구현 및 응용)

  • Sohn, Kyung-Rak
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.33 no.8
    • /
    • pp.1220-1225
    • /
    • 2009
  • In this paper, a tunable fiber feedback laser based on the use of Sagnac loop filter and fiber Bragg grating (FBG) is proposed. The Sagnac loop filter using a high birefringence fiber provides precise 0.33-nm channel spacing as a multi-wavelength grid filter. Ni-Cr wire wound on the FBG is useful to induce the thermo-optic effect of the fiber. Two types of FBG structures, which have a different length of wire, are demonstrated to show the wavelength shift and separation. To tune FBG by resistant heat, some current is supplied into the wire. When the wavelength matched with one of the cavity modes of Sagnac loop filter, the mode-locked lasing is occurred. The electrical power sensitivity of the resonant wavelength is measured to 1.75pm/mW. This laser configuration can be applied the electrical power system for monitoring the power fluctuation.

Fabrication of an Optical Fiber Amplifier Using Long-period Fiber Gratings Formed by Periodically Arrayed Metal Wire (금속선의 주기적 배열로 유도된 장주기 격자를 이용한 이득 평탄화된 광섬유 증폭기 제작)

  • Sohn, Kyung-Rak;Hwang, Woong;Shim, June-Hwan
    • Journal of Navigation and Port Research
    • /
    • v.31 no.10
    • /
    • pp.833-837
    • /
    • 2007
  • In this study, we have fabricated a gain flattened erbium-doped optical fiber amplifier. Gain flattening filters were realized by the strain-induced long period fiber gratings, which are made of periodically arrayed metal wires. Using the filter of $550{\mu}m$ period, spontaneous emission amplified at C-band wavelength by a 980nm pumping laser was flattened within 1dB of gain ripple. The performance of the simultaneous multi channel amplification was measured using a fabry-perot laser diode. Amplification ratio was above 20dB. This amplifier can be applied to the long distance transmission system based on a wavelength division multiplexing for boosting an attenuated signal.

Fabrication of multiple fiber Bragg grating by holographic method and its application to the temperature sensor system (홀로그래픽 방법을 사용한 다중 광섬유 격자 제작과 이를 이용한 온도 센서 시스템)

  • Lee, Gyeong-Sin;Yu, Eun-Mi;Son, Ju-Yeon;Kim, Geun-Jin;Yun, Jae-Sun;Choe, Gi-Seon;Baek, Se-Jong;Im, Gi-Geon
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2009.02a
    • /
    • pp.295-296
    • /
    • 2009
  • 다중 브래그 파장의 안정성 확보하고 제작비용을 줄이기 위하여 본 연구에서는 하나의 위상마스크와 스텝당 0.004도의 분해능을 갖는 탤봇 간섭계(Talbot Interferometer)로 이루어진 홀로그래픽 격자제작장치를 구성하였다. C-밴드와 L-밴드 파장 범위 내의 다중 브래그 파장 특성을 실험적으로 확인하고, 이 방법을 사용하여 서로 다른 파장의 브래그 격자를 센서부로 두고, $1{\times}6$ 광분배기와 결합시켜 화학반응조 내의 액체 온도를 측정하는 시스템을 제작하였다.

  • PDF

Fabrication of Butt-Coupled SGDBR Laser Integrated with Semiconductor Optical Amplifier Having a Lateral Tapered Waveguide

  • Oh, Su-Hwan;Ko, Hyun-Sung;Kim, Ki-Soo;Lee, Ji-Myon;Lee, Chul-Wook;Kwon, Oh-Kee;Park, Sahng-Gii;Park, Moon-Ho
    • ETRI Journal
    • /
    • v.27 no.5
    • /
    • pp.551-556
    • /
    • 2005
  • We have demonstrated a high-power widely tunable sampled grating distributed Bragg reflector (SGDBR) laser integrated monolithically with a semiconductor optical amplifier (SOA) having a lateral tapered waveguide, which is the first to emit a fiber-coupled output power of more than 10 dBm using a planar buried heterostructure (PBH). The output facet reflectivity of the integrated SOA using a lateral tapered waveguide and two-layer AR coating of $TiO_2\;and\;SiO_2$ was lower than $3\;{\times}\;10^{-4}\;over$ a wide bandwidth of 85 nm. The spectra of 40 channels spaced by 50 GHz within the tuning range of 33 nm were obtained by a precise control of SG and phase control currents. A side-mode suppression ratio of more than 35 dB was obtained in the whole tuning range. Fiber-coupled output power of more than 11 dBm and an output power variation of less than 1 dB were obtained for the whole tuning range.

  • PDF

Fabrication of a Temperature-Compensating FBB Sensor for Measurement of Mechanical Strain (온도 보상형 Double FBG센서의 제작과 기계적 변형률 측정시험)

  • Jung, Dal-Woo;Kwon, Il-Bum;Choi, Nak-Sam
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.25 no.5
    • /
    • pp.356-361
    • /
    • 2005
  • A temperature-compensating double fiber Bragg grating(FBG) sensor having two different FBGs in one fiber line was proposed for real time measurement of mechanical normal strain in structures. Measurement of mechanical strains of the aluminum beam surface by the double FBG sensor was performed under various thermal conditions, and the results were compared with those of electrical resistance strain gage. The FBG sensor fabricated in this study was able to measure accurately the mechanical strains without containing any thermal strain component.

Spectrum Characteristics of 1.55 ${\mu}m$ PBH-DFB-LD (광통신용 1.55 ${\mu}m$ PBH-DFB-LD 스펙트럼 특성)

  • 장동훈;이중기;이승원;박경현;김정수;김홍만;황인덕;박형무
    • Korean Journal of Optics and Photonics
    • /
    • v.5 no.1
    • /
    • pp.120-124
    • /
    • 1994
  • PBH-DFB-LD emitting at $1.55\mu\textrm{m}$ wavelength has been fabricated for 2.5 Gbps optical fiber communications. For fabrication of PBH-DFB-LD. inteference expose for grating formation and 3-step LPE epitaxial growth was used. Fabricated PBH-DFB-LD operates in single longitudinal mode with more than 35dB SMSR and its threshold current is less than 15 mA. The operating wavelength is 1530-1550 nm with the temperature dependence of $0.9\AA/^{\circ}C$. Coupling coefficient(K) was estimated as $$97 cm^{-1} by means of stop-band measurement. PBH-DFB-LD fabricated in this experiment can be applicable as light source for 2.5 Gbps optical fiber communication system. ystem.

  • PDF

The Hydrogen Loading Method for FBG Fabrication (광섬유격자 제작을 위한 수소 처리 방법 연구)

  • Song, Jeong-Hwan;Lee, Kyung-Shik
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.37 no.7
    • /
    • pp.29-35
    • /
    • 2000
  • The relationship between calculated hydrogen molecular concentration in fiber core and measured index change during the grating growth is analyzed. The index change increases by ${\sim}2{\times}10^{-5}$ per 100ppm of $H_2$ concentration in standard telecommunication optical fiber and the defects related photosensitivity generate ${\sim}3.8{\times}10^{17}$ per 100ppm of $H_2$.

  • PDF

Papers : Simultaneous Monitoring of Strain and Temperature During and After Cure of Unsymmetric Cross - ply Composite Laminate Using Fiber Optic Sensors (논문 : 비대칭 직교적층 복합재료 적층판의 성형시 및 성형후 광섬유 센서를 이용한 변형률 및 온도의 동시 모니터링)

  • Gang,Hyeon-Gyu;Gang,Dong-Hun;Hong,Chang-Seon;Kim,Cheon-Gon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.30 no.1
    • /
    • pp.49-55
    • /
    • 2002
  • In this paper, we present the simulation monitoring of strain and temperature during and after the cure of unsymmetric composite laminate using fiber optic sensors. Fiber Bragg grating/extrinsic Fabry-Perot interferometric (FBG/EFPI) hybrid sensors are used to measure those measurands. The characteristic matrix of the sensor is analytically derived and measurements can be done without sensor calibration. A wavelength-swept fiber laser is utilised as a lighr source. Two FBG/EFPI sensors are embedded in a graphite/epoxy unsymmetric cross-ply composite laminate in different directions and different locations. We perform a real time monitoring of fabrication strains and temperatures at two points of the composite laminate during cure process in an autoclave. Also, the thermal strains and temperatures of the fabricated laminate are measured in a thermal chamber. Through these experiments, we can provide a basis for the efficient smart processing of composite and know the thermal behavior of unsymmetric cross-ply composite laminate.

Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film

  • Bogdanowicz, Robert;Sobaszek, Michał;Ficek, Mateusz;Gnyba, Marcin;Ryl, Jacek;Siuzdak, Katarzyna;Bock, Wojtek J.;Smietana, Mateusz
    • Journal of the Optical Society of Korea
    • /
    • v.19 no.6
    • /
    • pp.705-710
    • /
    • 2015
  • The fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ℃. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp3 content in B-NCD films and mean grain size in the range of 100-250 nm. The films deposited on the glass reference samples exhibit high refractive index (n=2.05 at λ=550 nm) and low extinction coefficient. Furthermore, cyclic voltammograms (CV) were recorded to determine the electrochemical window and reaction reversibility at the B-NCD fiber-based electrode. CV measurements in aqueous media consisting of 5 mM K3[Fe(CN)6] in 0.5 M Na2SO4 demonstrated a width of the electrochemical window up to 1.03 V and relatively fast kinetics expressed by a redox peak splitting below 500 mV. Moreover, thanks to high-n B-NCD overlay, the coated fibers can be also used for enhancing the sensitivity of long-period gratings (LPGs) induced in the fiber. The LPG is capable of measuring variations in refractive index of the surrounding liquid by tracing the shift in resonance appearing in the transmitted spectrum. Possible combined CV and LPG-based measurements are discussed in this work.