An optical length measuring system base on all-fiber optic interferometer is proposed. The theoretical analysis indicates that, when the two branches of the interferometer are equal, the output have the maximum cohere...An optical length measuring system base on all-fiber optic interferometer is proposed. The theoretical analysis indicates that, when the two branches of the interferometer are equal, the output have the maximum coherent intensity. Therefore, the optical length can be obtained by measuring the distance of collimator movement. Through the experiment and simulation, the impact of the signal-to-noise ratio and fluctuation of the coupling efficiency on null error has been obtained.展开更多
Environmental vibration causes mechanical deformation in optical fibers, which induces excess frequency noise in fiber-stabilized lasers. In order to solve such a problem, we propose an ultralow acceleration sensitivi...Environmental vibration causes mechanical deformation in optical fibers, which induces excess frequency noise in fiber-stabilized lasers. In order to solve such a problem, we propose an ultralow acceleration sensitivity fiber spool with symmetrically mounted structure. By numerical analysis with the finite element method, we obtain the optimal geometry parameters of the spool with which the horizontal and vertical acceleration sensitivity can be reduced to 3.25 × 10^-12/g and 5.38 × 10^-12/g respectively. Moreover, the structure features the insensitivity to the variation of geometry parameters,which will minimize the influence from numerical simulation error and manufacture tolerance.展开更多
By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Struc...By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Structural parameters are optimized for realizing normal switching function.Dependencies of switching characteristics on the slot waveguide parameters are investigated.For the silicon strip with dimension of 170 nm×300 nm,as the slot width varies from 50 nm to 100 nm,the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm,and the length of the whole device is only about 770–950 μm.The voltage-length product of this switching structure is only 0.17–0.35 V·mm,and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch,which is 6.69 V·mm.Compared with our previously reported MZI EO switches,this switch exhibits some superior characteristics,including low switching voltage,compact device size and small wavelength dependency.展开更多
This paper discussed the main parameters contributing to the measurement uncertainty of interferometric distance meter （IDM）. A simple and robust set-up is used to measure distance of about 12 cm with an expanded un...This paper discussed the main parameters contributing to the measurement uncertainty of interferometric distance meter （IDM）. A simple and robust set-up is used to measure distance of about 12 cm with an expanded uncertainty （ k = 2） of ±16.4 μm. The measurement uncertainty is found to be limited by the wavelength measurement accuracy. This set-up can be used to measure distances up to 56 m. It also enables easy determination of the point of equal path difference between the measuring and the reference arms. LabVIEW program is used for counting of the fringes and applying fast Fourier transfor- mation （FFT） to perform frequency selective filtration to the noise. Although the reported uncertainty does not represent the state-of-art uncertainty reached for similar distance, the measurement provides traceable measurement to the unit of length, the meter.展开更多
A novel scheme is proposed to transform a Gaussian optical pulse to a millimeter-wave （mm-wave） frequency modulation pulse by using a Fabry-Perot interferometer （FPI） for radio-over-fiber （ROF） system. It is sho...A novel scheme is proposed to transform a Gaussian optical pulse to a millimeter-wave （mm-wave） frequency modulation pulse by using a Fabry-Perot interferometer （FPI） for radio-over-fiber （ROF） system. It is shown that modulation frequency of mm-wave is determined by the optical path of the Fabry-Perot （F-P） cavity, and amplitude decay time and energy transfer efficiency axe related to the reflectivity of the F-P cavity mirror. The effect of pulse train extension on inter-symbol interference is also discussed.展开更多
We experimentally demonstrate a 4 × 4 nonblocking silicon thermo-optic(TO) switch fabric consisting of three stages of tunable generalized Mach–Zehnder interferometers. All 24 routing states for nonblocking swit...We experimentally demonstrate a 4 × 4 nonblocking silicon thermo-optic(TO) switch fabric consisting of three stages of tunable generalized Mach–Zehnder interferometers. All 24 routing states for nonblocking switching are characterized. The device's footprint is 4.6 mm × 1.0 mm. Measurements show that the worst cross talk of all switching states is-7.2 dB. The on-chip insertion loss is in the range of 3.7–13.1 dB. The average TO switching power consumption is 104.8 mW.展开更多
To investigate the physical properties of HII regions and some PNe about 4＇ in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RTT150 telescope （f/48） at TUBITA...To investigate the physical properties of HII regions and some PNe about 4＇ in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RTT150 telescope （f/48） at TUBITAK National Observatory （Antalya/Baklrhtepe, Turkey）. The spectrometer has a 4＇ circular field of view and a velocity resolution of 27.27 km s^-1 （a spectral resolving power of 11000） over a 200 km s^-1 spectral window near Hα. This work presents the details of the newly redesigned instrument for coude observations, the data reduction techniques and finally presents some physical results of our new Hα observations selected from the Reynolds et al. （2005） and Fich et al. （1990） papers. The DEFPOS system has been fully tested and the first observations of HII regions and PNe in the Galaxy are used to illustrate the power of the instrument. We feel that our first Fabry-Perot observations can provide a powerful tool for the study of objects with small angular size. In the future, we are planning to prepare a catalog including some physical properties such as radial velocity, line width, and intensity of some PNe and HII regions close to the 4＇ field of view.展开更多
We propose a novel optical time-to-live （TTL） processing scheme using asymmetric Mech-Zehnder inter-ferometer （AMZI） and Fabry-Perot semiconductor optical amplifier （FP-SOA）. AMZI transfers M TTL pulses into M-1...We propose a novel optical time-to-live （TTL） processing scheme using asymmetric Mech-Zehnder inter-ferometer （AMZI） and Fabry-Perot semiconductor optical amplifier （FP-SOA）. AMZI transfers M TTL pulses into M-1 pulses and two residual pulses with 6-dB power difference. FP-SOA enhances the power difference between the M - 1 pulses to the residual pulses to more than 10 dB. A numerical model is established for verifying the feasibility of this scheme.展开更多
To improve the sensitivity measurement of temperature sensors,a fiber optic temperature sensor structure based on the harmonic Vernier effect with two parallel fiber Sagnac interferometers(FSIs)is designed,and theoret...To improve the sensitivity measurement of temperature sensors,a fiber optic temperature sensor structure based on the harmonic Vernier effect with two parallel fiber Sagnac interferometers(FSIs)is designed,and theoretical analysis and experimental testing are conducted.The FSI consisting of two polarization maintaining fibers(PMFs)with lengths of 13.62 m and 15.05 m respectively is used to achieve the basic Vernier effect.Then by changing the length of one PMF to approximately i times that of the others,the FSI composed of two PMFs of 7.1 m and 15.05 m is used to achieve the first-order harmonic Vernier effect.Afterward,temperature sensing tests are conducted to observe the wavelength drift during temperature changes and ultimately achieve high sensitivity.The experimental results show that the temperature sensitivity of the sensor based on the first-order harmonic Vernier effect is-28.89 nm/℃,which is 17.09 times that of a single FSI structure(-1.69 nm/℃)and 1.84 times that of the sensitivity generated by the structure based on the basic Vernier effect(-15.69 nm/℃).The experimental results are consistent with the theoretical analysis.The structure proposed in this paper achieves drift measurement of 0.1℃ variation based on 1 drift,making the fiber optic temperature sensor applicable to related fields that requir e high precision temperature.The proposed temperature sensor has the simple structure,low production cost,high sensitivity,and broad application prospects.展开更多
A brief review of recent progress made in a range of in-fiber integrated interferometers for measuring is presented,with particular attention paid to the multi-core based in-fiber integrated techniques,which have the ...A brief review of recent progress made in a range of in-fiber integrated interferometers for measuring is presented,with particular attention paid to the multi-core based in-fiber integrated techniques,which have the potential to be exploited in a variety of wide applications.展开更多
In the field of oil well logging, real-time monitoring of the fluid flow parameter provides a scientific basis for oil and gas optimization exploration and increase in reservoir recovery, so a non-intrusive flow test ...In the field of oil well logging, real-time monitoring of the fluid flow parameter provides a scientific basis for oil and gas optimization exploration and increase in reservoir recovery, so a non-intrusive flow test method based on turbulent vibration was proposed. The specific length of the sensor fiber wound tightly around the outer wall of the pipe was connected with the optical fiber gratings at both ends, and the sensor fiber and the optical fiber gratings composed the flow sensing unit. The dynamic pressure was generated by the turbulence when fluid flows through the pipe, and the dynamic pressure resulted in the light phase shift of the sensor fiber. The phase information was demodulated by the fiber optic interferometer technology, time division multiplexing technology, and phase generated carrier modulation and demodulation techniques. The quadratic curve relationship between the phase change and flow rate was found by experimental data analysis, and the experiment confirmed the feasibility of the optical fiber flow test method with non-intrusion and achieved the real-time monitoring of the fluid flow.展开更多
We demonstrate a 12.5 Gb/s carrier-injection silicon Mach-Zehnder optical modulator.Under a nonreturn -zero（NRZ） pre-emphasized electrical drive signal with voltage swing of 6.3 V and forward bias of 0.7 V, the eye ...We demonstrate a 12.5 Gb/s carrier-injection silicon Mach-Zehnder optical modulator.Under a nonreturn -zero（NRZ） pre-emphasized electrical drive signal with voltage swing of 6.3 V and forward bias of 0.7 V, the eye is clearly opened with an extinction ratio of 8.4 dB.The device exhibits high modulation efficiency,with a figure of merit V_πL of 0.036 V·mm.展开更多
基金supported by the Fundamental Research Funds for the Central Universities under Grant No.E022050205
文摘An optical length measuring system base on all-fiber optic interferometer is proposed. The theoretical analysis indicates that, when the two branches of the interferometer are equal, the output have the maximum coherent intensity. Therefore, the optical length can be obtained by measuring the distance of collimator movement. Through the experiment and simulation, the impact of the signal-to-noise ratio and fluctuation of the coupling efficiency on null error has been obtained.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11034008 and 11274324)the Key Research Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-W02)
文摘Environmental vibration causes mechanical deformation in optical fibers, which induces excess frequency noise in fiber-stabilized lasers. In order to solve such a problem, we propose an ultralow acceleration sensitivity fiber spool with symmetrically mounted structure. By numerical analysis with the finite element method, we obtain the optimal geometry parameters of the spool with which the horizontal and vertical acceleration sensitivity can be reduced to 3.25 × 10^-12/g and 5.38 × 10^-12/g respectively. Moreover, the structure features the insensitivity to the variation of geometry parameters,which will minimize the influence from numerical simulation error and manufacture tolerance.
基金supported by the National Natural Science Foundation of China(Nos.61107021,61177027 and 61077074)the Ministry of Education of China(Nos.20110061120052 and 20120061130008)the Science and Technology Department of Jilin Province of China(No.20130522161JH)
文摘By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer,we propose a kind of Mach-Zehnder interferometer(MZI) electro-optic(EO) switch operated at 1 550 nm.Structural parameters are optimized for realizing normal switching function.Dependencies of switching characteristics on the slot waveguide parameters are investigated.For the silicon strip with dimension of 170 nm×300 nm,as the slot width varies from 50 nm to 100 nm,the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm,and the length of the whole device is only about 770–950 μm.The voltage-length product of this switching structure is only 0.17–0.35 V·mm,and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch,which is 6.69 V·mm.Compared with our previously reported MZI EO switches,this switch exhibits some superior characteristics,including low switching voltage,compact device size and small wavelength dependency.
文摘This paper discussed the main parameters contributing to the measurement uncertainty of interferometric distance meter （IDM）. A simple and robust set-up is used to measure distance of about 12 cm with an expanded uncertainty （ k = 2） of ±16.4 μm. The measurement uncertainty is found to be limited by the wavelength measurement accuracy. This set-up can be used to measure distances up to 56 m. It also enables easy determination of the point of equal path difference between the measuring and the reference arms. LabVIEW program is used for counting of the fringes and applying fast Fourier transfor- mation （FFT） to perform frequency selective filtration to the noise. Although the reported uncertainty does not represent the state-of-art uncertainty reached for similar distance, the measurement provides traceable measurement to the unit of length, the meter.
文摘A novel scheme is proposed to transform a Gaussian optical pulse to a millimeter-wave （mm-wave） frequency modulation pulse by using a Fabry-Perot interferometer （FPI） for radio-over-fiber （ROF） system. It is shown that modulation frequency of mm-wave is determined by the optical path of the Fabry-Perot （F-P） cavity, and amplitude decay time and energy transfer efficiency axe related to the reflectivity of the F-P cavity mirror. The effect of pulse train extension on inter-symbol interference is also discussed.
基金supported in part by the 863 program (2013AA014402)the National Natural Science Foundation of China (NSFC) (61422508)the Science and Technology Commission of Shanghai Municipality (STCSM) Project (14QA1402600)
文摘We experimentally demonstrate a 4 × 4 nonblocking silicon thermo-optic(TO) switch fabric consisting of three stages of tunable generalized Mach–Zehnder interferometers. All 24 routing states for nonblocking switching are characterized. The device's footprint is 4.6 mm × 1.0 mm. Measurements show that the worst cross talk of all switching states is-7.2 dB. The on-chip insertion loss is in the range of 3.7–13.1 dB. The average TO switching power consumption is 104.8 mW.
基金This work is supported by TUBITAK (the Scientific and Technical Research Council of Turkey) with grant number 104T252.
文摘To investigate the physical properties of HII regions and some PNe about 4＇ in size, a DEFPOS Fabry-Perot spectrometer has been redesigned and set up at the coude exit of the 150cm RTT150 telescope （f/48） at TUBITAK National Observatory （Antalya/Baklrhtepe, Turkey）. The spectrometer has a 4＇ circular field of view and a velocity resolution of 27.27 km s^-1 （a spectral resolving power of 11000） over a 200 km s^-1 spectral window near Hα. This work presents the details of the newly redesigned instrument for coude observations, the data reduction techniques and finally presents some physical results of our new Hα observations selected from the Reynolds et al. （2005） and Fich et al. （1990） papers. The DEFPOS system has been fully tested and the first observations of HII regions and PNe in the Galaxy are used to illustrate the power of the instrument. We feel that our first Fabry-Perot observations can provide a powerful tool for the study of objects with small angular size. In the future, we are planning to prepare a catalog including some physical properties such as radial velocity, line width, and intensity of some PNe and HII regions close to the 4＇ field of view.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 60572008.
文摘We propose a novel optical time-to-live （TTL） processing scheme using asymmetric Mech-Zehnder inter-ferometer （AMZI） and Fabry-Perot semiconductor optical amplifier （FP-SOA）. AMZI transfers M TTL pulses into M-1 pulses and two residual pulses with 6-dB power difference. FP-SOA enhances the power difference between the M - 1 pulses to the residual pulses to more than 10 dB. A numerical model is established for verifying the feasibility of this scheme.
基金supported by the Primary Research and Development Plan of Zhejiang Province,China(Grant No.2023C03014)the Key Research and Development Program of Zhejiang Province,China(Grant No.2022C03037).
文摘To improve the sensitivity measurement of temperature sensors,a fiber optic temperature sensor structure based on the harmonic Vernier effect with two parallel fiber Sagnac interferometers(FSIs)is designed,and theoretical analysis and experimental testing are conducted.The FSI consisting of two polarization maintaining fibers(PMFs)with lengths of 13.62 m and 15.05 m respectively is used to achieve the basic Vernier effect.Then by changing the length of one PMF to approximately i times that of the others,the FSI composed of two PMFs of 7.1 m and 15.05 m is used to achieve the first-order harmonic Vernier effect.Afterward,temperature sensing tests are conducted to observe the wavelength drift during temperature changes and ultimately achieve high sensitivity.The experimental results show that the temperature sensitivity of the sensor based on the first-order harmonic Vernier effect is-28.89 nm/℃,which is 17.09 times that of a single FSI structure(-1.69 nm/℃)and 1.84 times that of the sensitivity generated by the structure based on the basic Vernier effect(-15.69 nm/℃).The experimental results are consistent with the theoretical analysis.The structure proposed in this paper achieves drift measurement of 0.1℃ variation based on 1 drift,making the fiber optic temperature sensor applicable to related fields that requir e high precision temperature.The proposed temperature sensor has the simple structure,low production cost,high sensitivity,and broad application prospects.
基金This work was partially supported by the National Nature Science Foundation of China,under grant number 60877046,60707013 and 60807032,to the Harbin Engineering University.
文摘A brief review of recent progress made in a range of in-fiber integrated interferometers for measuring is presented,with particular attention paid to the multi-core based in-fiber integrated techniques,which have the potential to be exploited in a variety of wide applications.
文摘In the field of oil well logging, real-time monitoring of the fluid flow parameter provides a scientific basis for oil and gas optimization exploration and increase in reservoir recovery, so a non-intrusive flow test method based on turbulent vibration was proposed. The specific length of the sensor fiber wound tightly around the outer wall of the pipe was connected with the optical fiber gratings at both ends, and the sensor fiber and the optical fiber gratings composed the flow sensing unit. The dynamic pressure was generated by the turbulence when fluid flows through the pipe, and the dynamic pressure resulted in the light phase shift of the sensor fiber. The phase information was demodulated by the fiber optic interferometer technology, time division multiplexing technology, and phase generated carrier modulation and demodulation techniques. The quadratic curve relationship between the phase change and flow rate was found by experimental data analysis, and the experiment confirmed the feasibility of the optical fiber flow test method with non-intrusion and achieved the real-time monitoring of the fluid flow.
基金supported by the National Natural Science Foundation of China(No.60977037)
文摘We demonstrate a 12.5 Gb/s carrier-injection silicon Mach-Zehnder optical modulator.Under a nonreturn -zero（NRZ） pre-emphasized electrical drive signal with voltage swing of 6.3 V and forward bias of 0.7 V, the eye is clearly opened with an extinction ratio of 8.4 dB.The device exhibits high modulation efficiency,with a figure of merit V_πL of 0.036 V·mm.
