A new Michelson interferometer based on fiber Bragg grating（FBG） is demonstrated. FBCs are used as reflectors, and the laser is replaced by a broadband source as input light in this interferometer. To demodulate the...A new Michelson interferometer based on fiber Bragg grating（FBG） is demonstrated. FBCs are used as reflectors, and the laser is replaced by a broadband source as input light in this interferometer. To demodulate the signals, a 3 × 3 coupler is used as a splitter. By combining with software demodulation, the outer interference can be obtained from the outputs of the interferometer. This kind of interferometer can also be wavelength-multiplexed easily by composing a series Michelson interferometer. The experiment results show that the clear interference fringe can be obtained by adjusting the path difference to make it less than interference length of FBG. The signals are also demodulated.展开更多
The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, ...The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, associated with the phase mask periodicity were observed. However, when phase mask orders other than ＋1 were absent during fabrication the features at 1552 nm were not evident.展开更多
The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP senso...The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP sensors after irradiation was stable,while the temperature sensitivity of FBG sensors was unstable,and both wavelengths displayed a shift.These findings offer the possibility for the application of FP pressure sensors in the gamma radiation environments,and FBG sensors require further research to be suitable for application in the nuclear radiation environments.展开更多
A simple nanostrain direct current （DC） measurement system based on a chirped Bragg grating Fabry-Perot （FP） structure is presented. The FP cavity, formed between the chirped fiber Bragg grating （CFBG） and the f...A simple nanostrain direct current （DC） measurement system based on a chirped Bragg grating Fabry-Perot （FP） structure is presented. The FP cavity, formed between the chirped fiber Bragg grating （CFBG） and the fiber end face, presents an aperiodic behavior due to the CFBG. A laser located in the fringe pattern slope is used to interrogate the sensing head. The optical power parameter is analyzed when strain is applied, for long and short period fringe pattern wavelengths, and sensitivities of-2.87 μW/με and-5.48μW/με are respectively obtained. This configuration presents a resolution of 70 ε.展开更多
Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavel...Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.展开更多
This paper presents a review of recent progress in simultaneous measurement of multiparameters including strain, temperature, vibration, transverse load, based on the combinations of extrinsic fiber-optic Fabry-Perot ...This paper presents a review of recent progress in simultaneous measurement of multiparameters including strain, temperature, vibration, transverse load, based on the combinations of extrinsic fiber-optic Fabry-Perot interferometers and fiber gratings.展开更多
The Talbot interferometer used for writing fiber Bragg grating(FBG)is analyzed effectively in this paper.Based on electromagnetic theory,a computing model of the Talbot interferometer is established with the temporal ...The Talbot interferometer used for writing fiber Bragg grating(FBG)is analyzed effectively in this paper.Based on electromagnetic theory,a computing model of the Talbot interferometer is established with the temporal and the spatial coherence taken into account and with the turning angle of the reflectors as a critical parameter.The model can provide a more detailed and precise information about the interference field and is used to study the effect of the turning error of the reflectors in writing FBG.The calculation result shows that the turning error has an important effect on the visibility of the far interference field.展开更多
A novel fiber magnetic sensor based on the fiber Bragg grating Fabry-Perot （FBG-FP） cavity ring-down technique with pulse laser injection is proposed and demonstrated theoretically. A general expression of the inten...A novel fiber magnetic sensor based on the fiber Bragg grating Fabry-Perot （FBG-FP） cavity ring-down technique with pulse laser injection is proposed and demonstrated theoretically. A general expression of the intensity of the output electric field is derived, and the effect of the external magnetic field on the ring-down time is discussed. The results show that the output light intensity and the ring-down time of the FBG-FP cavity are in the inverse proportion to the magnitude of the external magnetic field. Our results demonstrate the new concept of the fiber magnetic sensor with the FBG-FP cavity ring-down spectroscopy and the technical feasibility.展开更多
We experimentally demonstrate the simultaneous generation of tunable multi-wavelength picosecond laser pulses using a self-seeding configuration that consists of a gain-switched Fabry-Perot laser diode （FPLD） with a...We experimentally demonstrate the simultaneous generation of tunable multi-wavelength picosecond laser pulses using a self-seeding configuration that consists of a gain-switched Fabry-Perot laser diode （FPLD） with an external cavity formed by a tilted multimode fiber Bragg grating. Dual- and triple-wavelength pulses are obtained and tuned in a flexible manner by changing the temperature of the FPLD. The side mode suppression ratio larger than 25 dB is achieved at different dual- and triple-wavelengths and the typical pulsewidth of the output pulses is ,-70 ps. In the experiment, the wavelength separation can be narrowed to 0.57 nm.展开更多
This article reviews author＇s research work on fiber-optic sensors over the last twenty years. It includes two aspects： low-coherence interferometric sensors （LCI） and fiber Bragg grating （FBG） sensors. For LCI ...This article reviews author＇s research work on fiber-optic sensors over the last twenty years. It includes two aspects： low-coherence interferometric sensors （LCI） and fiber Bragg grating （FBG） sensors. For LCI sensors, author＇s work mainly focuses on the interrogation and multiplexing methods for Fizeau and Fabry-Perot interferometric sensors at the University of Kent at Canterbury （UKC）, UK, and study on novel Fabry-Perot interferometric sensors and their multiplexing methods at Chongqing University （CQU） and University of Electronic Science ＆ Technology of China （UESTC）, China, respectively. For FBG sensors, a number of multiplexing schemes are proposed and demonstrated at UKC, and then novel methods for realization of multi-parameter measurement and long-distance measurement based on the FBG sensor and its combination with other optical fiber sensors are also reported at CQU ＆ UESTC. Thus, author＇s study on these two topics can be diviaed into two periods, at UKC and at CQU ＆ UESTC, China. This review is presented in such a time sequence.展开更多
The characteristics of transmission spectra for the all fiber, multi-cavity Fabry- Perot （FP） configuration based on fiber Bragg gratings （FBG） are theoretically analyzed and modeled. The general transmission matr...The characteristics of transmission spectra for the all fiber, multi-cavity Fabry- Perot （FP） configuration based on fiber Bragg gratings （FBG） are theoretically analyzed and modeled. The general transmission matrix function for the structure with any number of cavities is derived, and explicit expression of the power trans- mission coefficient for symmetrical two-cavity FP is presented. The general condi- tions for flat-top single resonant peak at the central wavelength in FBG stop band are derived and verified in the numerical simulation section. The transmission peaks of single-cavity and two-cavity FP structures are compared and discussed, and results show that compared to the single-cavity FP, flatness of the top and steepness at the edge of transmission peak can be improved by introducing one more cavity. The resonant transmission peak properties of two-cavity structure are investigated in detail for various values of cavity length and FBGs with different reflection characteristics, and the design guidelines for transmission-type filters are presented. The results show that the steepness of peak slope can be improved by increase of FBG reflectivities, and these kinds of filters can be used as nar- row-band single-channel selectors and multi-channel wavelength de-multiplexing by properly choosing the length of cavities and reflectivities of FBGs.展开更多
In this letter, a novel mechanism of hybrid optical bistability is proposed by using nonlinear mechanism in the frequency domain. This device is based on electro-optical feedback through the fiber Bragg grating on pie...In this letter, a novel mechanism of hybrid optical bistability is proposed by using nonlinear mechanism in the frequency domain. This device is based on electro-optical feedback through the fiber Bragg grating on piezoelectric transducer (PZT) to tune continuous wave (CW) fiber laser. The optical bistable characteristics for two manners of separately alternating input power and bias voltage are discussed. The smallest wavelength shift of the order of 0.001 nm needed to realize a switching process in this optical bistability device is estimated. The potential applications of this device in the optical fiber sensor technique are also discussed.展开更多
基金the National Natural Science Foundation of China (60277015) and the National"863"Program Project (2004AA616020)
文摘A new Michelson interferometer based on fiber Bragg grating（FBG） is demonstrated. FBCs are used as reflectors, and the laser is replaced by a broadband source as input light in this interferometer. To demodulate the signals, a 3 × 3 coupler is used as a splitter. By combining with software demodulation, the outer interference can be obtained from the outputs of the interferometer. This kind of interferometer can also be wavelength-multiplexed easily by composing a series Michelson interferometer. The experiment results show that the clear interference fringe can be obtained by adjusting the path difference to make it less than interference length of FBG. The signals are also demodulated.
基金supported by the Australian Research Council under Grant No. DP0773999.
文摘The use of a phase mask with 536 nm uniform pitch allowed the fabrication of a fiber Bragg grating for use at a Bragg wavelength of 785 nm. Reflection and transmission features at 1552 nm, twice the Bragg wavelength, associated with the phase mask periodicity were observed. However, when phase mask orders other than ＋1 were absent during fabrication the features at 1552 nm were not evident.
基金This work was funded by the National Science Foundation of China(NCSF)(Grant No.51875091)the Study and Application of Full-model Impact Dynamic Fretting Damage Test System in the Extreme Environment(Grant No.51627806)+3 种基金Research on Application of Optical Fiber Sensing in Nuclear Power(Grant No.180046)Optical Fiber Sensing and Processing Prototype for Nuclear Field Key Parameter Measurement(Grant No.191091)Data Acquisition and Post-processing Software Development for Integrated Fiber Optic Sensors(Grant No.190167)the State 111 Project(Grant No.B14039).
文摘The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP sensors after irradiation was stable,while the temperature sensitivity of FBG sensors was unstable,and both wavelengths displayed a shift.These findings offer the possibility for the application of FP pressure sensors in the gamma radiation environments,and FBG sensors require further research to be suitable for application in the nuclear radiation environments.
文摘A simple nanostrain direct current （DC） measurement system based on a chirped Bragg grating Fabry-Perot （FP） structure is presented. The FP cavity, formed between the chirped fiber Bragg grating （CFBG） and the fiber end face, presents an aperiodic behavior due to the CFBG. A laser located in the fringe pattern slope is used to interrogate the sensing head. The optical power parameter is analyzed when strain is applied, for long and short period fringe pattern wavelengths, and sensitivities of-2.87 μW/με and-5.48μW/με are respectively obtained. This configuration presents a resolution of 70 ε.
基金supported by the National“863” Project of China(2007AA01Z258)the National Natural Science Foundation of China(60771008)+2 种基金Program for New Century Excellent Talents in University(NCET-06-0076)Beijing Natural Science Foundation(4082024)the Beijing Jiaotong University Foundation(2006XM003)
文摘Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.
文摘This paper presents a review of recent progress in simultaneous measurement of multiparameters including strain, temperature, vibration, transverse load, based on the combinations of extrinsic fiber-optic Fabry-Perot interferometers and fiber gratings.
基金supported by the National Nature Science Foundation of China (No.60077023).
文摘The Talbot interferometer used for writing fiber Bragg grating(FBG)is analyzed effectively in this paper.Based on electromagnetic theory,a computing model of the Talbot interferometer is established with the temporal and the spatial coherence taken into account and with the turning angle of the reflectors as a critical parameter.The model can provide a more detailed and precise information about the interference field and is used to study the effect of the turning error of the reflectors in writing FBG.The calculation result shows that the turning error has an important effect on the visibility of the far interference field.
文摘A novel fiber magnetic sensor based on the fiber Bragg grating Fabry-Perot （FBG-FP） cavity ring-down technique with pulse laser injection is proposed and demonstrated theoretically. A general expression of the intensity of the output electric field is derived, and the effect of the external magnetic field on the ring-down time is discussed. The results show that the output light intensity and the ring-down time of the FBG-FP cavity are in the inverse proportion to the magnitude of the external magnetic field. Our results demonstrate the new concept of the fiber magnetic sensor with the FBG-FP cavity ring-down spectroscopy and the technical feasibility.
基金supported by the Project of Shanghai Science & Technology Committee (Nos. 09530500600 and 09PJ1404600)the Key Project of Shanghai Education Committee (No. 09ZZ92)+1 种基金partly supported by the Shanghai Leading Academic Discipline Project under Grant No. S30108.the support provided by the Program for Professors of Special Appointment (Eastern Scholar) at the Shanghai Institutions of Higher Learning, China
文摘We experimentally demonstrate the simultaneous generation of tunable multi-wavelength picosecond laser pulses using a self-seeding configuration that consists of a gain-switched Fabry-Perot laser diode （FPLD） with an external cavity formed by a tilted multimode fiber Bragg grating. Dual- and triple-wavelength pulses are obtained and tuned in a flexible manner by changing the temperature of the FPLD. The side mode suppression ratio larger than 25 dB is achieved at different dual- and triple-wavelengths and the typical pulsewidth of the output pulses is ,-70 ps. In the experiment, the wavelength separation can be narrowed to 0.57 nm.
文摘This article reviews author＇s research work on fiber-optic sensors over the last twenty years. It includes two aspects： low-coherence interferometric sensors （LCI） and fiber Bragg grating （FBG） sensors. For LCI sensors, author＇s work mainly focuses on the interrogation and multiplexing methods for Fizeau and Fabry-Perot interferometric sensors at the University of Kent at Canterbury （UKC）, UK, and study on novel Fabry-Perot interferometric sensors and their multiplexing methods at Chongqing University （CQU） and University of Electronic Science ＆ Technology of China （UESTC）, China, respectively. For FBG sensors, a number of multiplexing schemes are proposed and demonstrated at UKC, and then novel methods for realization of multi-parameter measurement and long-distance measurement based on the FBG sensor and its combination with other optical fiber sensors are also reported at CQU ＆ UESTC. Thus, author＇s study on these two topics can be diviaed into two periods, at UKC and at CQU ＆ UESTC, China. This review is presented in such a time sequence.
基金Supported by the Fund of Beijing Jiaotong University (Grant No. 2006XZ010)the Program for New Century Excellent Telants in University (Grant No. NCET-06-0076)
文摘The characteristics of transmission spectra for the all fiber, multi-cavity Fabry- Perot （FP） configuration based on fiber Bragg gratings （FBG） are theoretically analyzed and modeled. The general transmission matrix function for the structure with any number of cavities is derived, and explicit expression of the power trans- mission coefficient for symmetrical two-cavity FP is presented. The general condi- tions for flat-top single resonant peak at the central wavelength in FBG stop band are derived and verified in the numerical simulation section. The transmission peaks of single-cavity and two-cavity FP structures are compared and discussed, and results show that compared to the single-cavity FP, flatness of the top and steepness at the edge of transmission peak can be improved by introducing one more cavity. The resonant transmission peak properties of two-cavity structure are investigated in detail for various values of cavity length and FBGs with different reflection characteristics, and the design guidelines for transmission-type filters are presented. The results show that the steepness of peak slope can be improved by increase of FBG reflectivities, and these kinds of filters can be used as nar- row-band single-channel selectors and multi-channel wavelength de-multiplexing by properly choosing the length of cavities and reflectivities of FBGs.
文摘In this letter, a novel mechanism of hybrid optical bistability is proposed by using nonlinear mechanism in the frequency domain. This device is based on electro-optical feedback through the fiber Bragg grating on piezoelectric transducer (PZT) to tune continuous wave (CW) fiber laser. The optical bistable characteristics for two manners of separately alternating input power and bias voltage are discussed. The smallest wavelength shift of the order of 0.001 nm needed to realize a switching process in this optical bistability device is estimated. The potential applications of this device in the optical fiber sensor technique are also discussed.
