The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced at...The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation （RIA） self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation （RIBA） at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward （DPB） configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad （Si） gamma-ray irradiation.展开更多
The effects of color centers＇ absorption on fibers and interferometric fiber optical gyroscopes（IFOGs） are studied in the paper. The irradiation induced attenuation（RIA） spectra of three types of polarization-mai...The effects of color centers＇ absorption on fibers and interferometric fiber optical gyroscopes（IFOGs） are studied in the paper. The irradiation induced attenuation（RIA） spectra of three types of polarization-maintaining fibers（PMFs）, i.e.,P-doped, Ge-doped, and pure silica, irradiated at 100 Gy and 1000 Gy are measured in a wavelength range from 1100 nm to1600 nm and decomposed according to the Gaussian model. The relationship of the color centers absorption intensity with radiation dose is investigated based on a power model. Furthermore, the effects of all color centers＇ absorption on RIA and mean wavelength shifts（MWS） at 1300 nm and 1550 nm are discussed respectively. Finally, the random walk coefficient（RWC） degradation induced from RIA and the scale factor error induced by MWS of the IFOG are simulated and tested at a wavelength of 1300 nm. This research will contribute to the applications of the fibers in radiation environments.展开更多
We investigated the steady state gamma-ray radiation response of pure-silica-core photonic crystal fibers（PSC-PCFs）under an accumulated dose of 500 Gy and a dose rate of 2.38 Gy/min. The radiation-induced attenuatio...We investigated the steady state gamma-ray radiation response of pure-silica-core photonic crystal fibers（PSC-PCFs）under an accumulated dose of 500 Gy and a dose rate of 2.38 Gy/min. The radiation-induced attenuation（RIA） spectra in the near-infrared region from 800 nm to 1700 nm were obtained. We find that the RIA at 1550 nm is related with hydroxyl（OH^-） absorption defects in addition to the identified self-trapped hole（STH） defects. Moreover, it is proposed and demonstrated that reduced OH^-absorption defects can decrease the RIA at 1550 nm. The RIA at 1550 nm has effectively declined from 27.7 d B/km to 3.0 dB/km through fabrication improvement. Preliminary explanations based on the unique fabrication processes were given to interpret the RIA characteristics of PSC-PCFs. The results show that the PSC-PCFs,which offer great advantages over conventional fibers, are promising and applicable to fiber sensors in harsh environments.展开更多
A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg gratin...A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating(FBG)underg-ray irradiation environment.The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18℃to 40℃before theγ-ray irradiation were about 4.57´10^(-4)dB/℃and 5.48 pm/℃,respectively.The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under theγ-ray irradiation with the total dose of 22.85 kGy at 35℃were about 0.03 dB/m and 0.12 nm,respectively,with theγ-ray irradiation sensitivity of 5.25´10^(-3)pm/Gy.The temperature and theγ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18℃to 40℃and theγ-ray irradiation with the total dose of 22.85 kGy at 35℃,respectively.Furthermore,the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of theγ-ray irradiation.However,no influence on the reflection power of the Bragg wavelengths and the full width at half maximum(FWHM)bandwidth under temperature and theγ-ray irradiation change was found.Also,after theγ-ray irradiation with the dose of 22.85 kGy,no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.展开更多
The effects of gamma ray(γ-ray)radiation and electron beam(e-beam)radiation on Rayleigh scattering coefficient in single-mode fiber are experimentally investigated.Utilizing an optical time domain reflectometry(OTDR)...The effects of gamma ray(γ-ray)radiation and electron beam(e-beam)radiation on Rayleigh scattering coefficient in single-mode fiber are experimentally investigated.Utilizing an optical time domain reflectometry(OTDR),the power distribution curves of the irradiated fibers are obtained to retrieve the corresponding radiation-induced attenuation(RIA).Based on the backscattering power levels and the measured RIAs,the Rayleigh scattering coefficients can be characterized quantitatively for each fiber sample.Under the given radiation conditions,Rayleigh scattering coefficients have been changed very little while RIAs have been changed significantly.Furthermore,simulations have been implemented to verify the validity of the measured Rayleigh scattering coefficient,including the splicing points.展开更多
基金supported by the Special Fund for Development of National Major Scientific Instruments of China(Grant No.2013YQ04081504)the Program for Innovative Research Team in University,China(Grant No.IRT 1203)
文摘The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation （RIA） self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation （RIBA） at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward （DPB） configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad （Si） gamma-ray irradiation.
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China
文摘The effects of color centers＇ absorption on fibers and interferometric fiber optical gyroscopes（IFOGs） are studied in the paper. The irradiation induced attenuation（RIA） spectra of three types of polarization-maintaining fibers（PMFs）, i.e.,P-doped, Ge-doped, and pure silica, irradiated at 100 Gy and 1000 Gy are measured in a wavelength range from 1100 nm to1600 nm and decomposed according to the Gaussian model. The relationship of the color centers absorption intensity with radiation dose is investigated based on a power model. Furthermore, the effects of all color centers＇ absorption on RIA and mean wavelength shifts（MWS） at 1300 nm and 1550 nm are discussed respectively. Finally, the random walk coefficient（RWC） degradation induced from RIA and the scale factor error induced by MWS of the IFOG are simulated and tested at a wavelength of 1300 nm. This research will contribute to the applications of the fibers in radiation environments.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61575012 and 61575013)the National Key Scientific Instrument and Equipment Development Project,China(Grant No.2013YQ040877)
文摘We investigated the steady state gamma-ray radiation response of pure-silica-core photonic crystal fibers（PSC-PCFs）under an accumulated dose of 500 Gy and a dose rate of 2.38 Gy/min. The radiation-induced attenuation（RIA） spectra in the near-infrared region from 800 nm to 1700 nm were obtained. We find that the RIA at 1550 nm is related with hydroxyl（OH^-） absorption defects in addition to the identified self-trapped hole（STH） defects. Moreover, it is proposed and demonstrated that reduced OH^-absorption defects can decrease the RIA at 1550 nm. The RIA at 1550 nm has effectively declined from 27.7 d B/km to 3.0 dB/km through fabrication improvement. Preliminary explanations based on the unique fabrication processes were given to interpret the RIA characteristics of PSC-PCFs. The results show that the PSC-PCFs,which offer great advantages over conventional fibers, are promising and applicable to fiber sensors in harsh environments.
基金This work was partially supported by the Korea Electric Power Corporation Research Institute(Grant No.KEPRI-16-23)the Korea Industrial Complex Corporation Industrial Cluster Competitiveness Enhancement Project(Grant No.RGJ18014),South Korea.
文摘A new radiation-hard germano-silicate glass optical fiber with a pure silica glass buffer and a boron-doped silica glass inner cladding was fabricated for temperature sensor application based on the fiber Bragg grating(FBG)underg-ray irradiation environment.The temperature dependences of optical attenuation at 1550.5 nm and Bragg reflection wavelength shift from 18℃to 40℃before theγ-ray irradiation were about 4.57´10^(-4)dB/℃and 5.48 pm/℃,respectively.The radiation-induced optical attenuation at 1550.5 nm and the radiation-induced Bragg reflection wavelength shift under theγ-ray irradiation with the total dose of 22.85 kGy at 35℃were about 0.03 dB/m and 0.12 nm,respectively,with theγ-ray irradiation sensitivity of 5.25´10^(-3)pm/Gy.The temperature and theγ-ray irradiation dependence of optical attenuation at 1550.5 nm in the FBG written fiber with boron-doped silica glass inner cladding were about 6 times and 4 times lower than that in the FBG written fiber without boron-doped silica glass inner cladding under a temperature change from 18℃to 40℃and theγ-ray irradiation with the total dose of 22.85 kGy at 35℃,respectively.Furthermore,the effect of temperature increase on the Bragg reflection wavelength of the FBG written fiber with boron-doped silica inner cladding was much larger about 1000 times than that of theγ-ray irradiation.However,no influence on the reflection power of the Bragg wavelengths and the full width at half maximum(FWHM)bandwidth under temperature and theγ-ray irradiation change was found.Also,after theγ-ray irradiation with the dose of 22.85 kGy,no significant change in the refractive index was found but the residual stresses developed in the fiber were slightly relaxed or retained.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.41527805 and 61635005)Sichuan Youth Science and Technology Foundation(Grant No.2016JQ0034)+3 种基金the 111 Project(Grant No.B14039)The Romanian authors acknowledge the support of the Romanian Executive Agency for Higher Education,Research,Development and Innovation Funding(Grant No.UEFISCDI),under the contract“Sensor Systems for Secure Operation of Critical Installations”.G.Peng acknowledges the support by Science and Technology Commission of Shanghai Municipality,China(Grant Nos.SKLSFO2015-01 and 15220721500)by the Hisilicon Innovation Research Program(HIRP)(Grant No.HO2017050001CZ).
文摘The effects of gamma ray(γ-ray)radiation and electron beam(e-beam)radiation on Rayleigh scattering coefficient in single-mode fiber are experimentally investigated.Utilizing an optical time domain reflectometry(OTDR),the power distribution curves of the irradiated fibers are obtained to retrieve the corresponding radiation-induced attenuation(RIA).Based on the backscattering power levels and the measured RIAs,the Rayleigh scattering coefficients can be characterized quantitatively for each fiber sample.Under the given radiation conditions,Rayleigh scattering coefficients have been changed very little while RIAs have been changed significantly.Furthermore,simulations have been implemented to verify the validity of the measured Rayleigh scattering coefficient,including the splicing points.
