A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fibe...A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fiber,SMF)together with an optical fiber fusion splicer,establishing two distinct centimeter-level optical transmission paths.Since the high-order modes in NCF transmit near-infrared light more sensitively to curvature-induced energy leakage than the fundamental mode in SMF,the near-infrared high-order mode light leaks out of NCF when the curvature changes,causing the MTP-MZI transmission spectrum to change.By ana⁃lyzing the relationship between the curvature,transmission spectrum,and spatial frequency spectrum,the modes involved in the interference can be studied,thereby revealing the mode transmission characteristics of near-infra⁃red light in optical fibers.In the verification experiments,higher-order modes were excited by inserting a novel hollow-core fiber(HCF)into the MTP-MZI.When the curvature of the MTP-MZI changes,the near-infrared light high-order mode introduced into the device leaks out,causing the transmission spectrum to return to its origi⁃nal state before bending and before the HCF was spliced.The experimental results demonstrate that the MTP-MZI mode monitor can monitor the fiber modes introduced from the external environment,providing both theoretical and experimental foundations for near-infrared all-fiber mode monitoring in optical information systems.展开更多
A polarization-maintaining （PM） fiber Mach-Zehnder （MZ） interferometer has been established to measure the EO effect of very thin film materials with optical anisotropy. Unlike a common MZ interferometer, all the ...A polarization-maintaining （PM） fiber Mach-Zehnder （MZ） interferometer has been established to measure the EO effect of very thin film materials with optical anisotropy. Unlike a common MZ interferometer, all the components are connected via polarization-maintaining fibers. At the same time, a polarized DFB laser with a maximum power output of 10mW is adopted as the light source to induce a large extinction ratio. Here,we take it to determine the electro-optical coefficients of a very thin superlattice structure with GaAs, KTP, and GaN as comparative samples. The measured EO coefficients show good comparability with the others.展开更多
Many delayed-choice experiments based on Mach-Zehnder interferometers （MZI） have been considered and made to address the fundamental problem of wave-particle duality. Conventional wisdom long holds that by inserting...Many delayed-choice experiments based on Mach-Zehnder interferometers （MZI） have been considered and made to address the fundamental problem of wave-particle duality. Conventional wisdom long holds that by inserting or removing the second beam splitter （BS2） in a controllable way, microscopic particles （photons, electrons, etc.） transporting within the MZI can lie in the quantum superposition of the wave and particle state as ψ= aw ψ wave ＋ ap ψ particle. Here we present an alternative interpretation to these delayed-choice experiments. We notice that as the BS2 is purely classical, the inserting and removing operation of the BS2 imposes a time- modulated Hamiltonian H mod （t） = a（t）Hin ＋ b（t）Hout, instead of a quantum superposition of H in and Hour as H = awHin ＋ apHout, to act upon the incident wave function. Solution of this quantum scattering problem, rather than the long held quantum eigen-problem yields a synchronically time-modulated output wave function as ψ mod （t） = a（t） ψ wave ＋b（t） ψ particle, instead of the stationary quantum superposition state ψ = aw ψ wave ＋ ap ψ particle. As a result, the probability of particle output from the MZI behaves as if they are in the superposition of the wave and particle state when many events over time accumulation are counted and averaged. We expect that these elementary but insightful analyses will shed a new light on exploring basic physics beyond the long-held wisdom of wave-particle duality and the principle of complementarity.展开更多
A distributed optical fiber disturbance detection system consisted of a Sagnac interferometer and a Mach-Zehnder interferometer is demonstrated. Two interferometers outputs are connected to an electric band-pass filte...A distributed optical fiber disturbance detection system consisted of a Sagnac interferometer and a Mach-Zehnder interferometer is demonstrated. Two interferometers outputs are connected to an electric band-pass filter via a detector respectively. The central frequencies of the two filters are selected adaptively according to the disturbance frequency. The disturbance frequency is obtained by either frequency spectrum of the two interferometers outputs. An alarm is given out only when the Sagnac interferometer output is changed. A disturbance position is determined by calculating a time difference with a cross-correlation method between the filter output connected to the Sagnac interferometer and derivative of the filter output connected to the Mach-Zehnder interferometer. The frequency spectrum, derivative and cross-correlation are obtained by a signal processing system. Theory analysis and simulation results are presented. They show that the system structure and location method are effective, accurate, and immune to environmental variations.展开更多
An in-fiber Mach-Zehnder interferometer for strain measurement is proposed and experimentally demonstrated. The sensor consists of a taper followed by a short section of a multi-mode fiber （MMF） and a dispersion com...An in-fiber Mach-Zehnder interferometer for strain measurement is proposed and experimentally demonstrated. The sensor consists of a taper followed by a short section of a multi-mode fiber （MMF） and a dispersion com- pensating fiber （DCF）, which is sandwiched between two single mode fibers （SMFs）. The taper is used as a fiber coupler to excite cladding modes in the SMF, and these cladding modes transmit within the MMF and the DCF. The core mode and the cladding modes interfere in the DCF SMF fusion point to form intermodal interference. A well-defined interference spectrum is obtained in the experiment. Selected interference dips are used to measure the strain changes. The experimental results show that this device is sensitive to strain with the wavelength-referenced sensitivity of 2.6 pm/με and the power-referenced sensitivity of 0. 0027 dB/με, respectively.展开更多
This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, ...This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, the thermal boundary layer and its thickness are quantitatively visualized and measured using a Mach-Zehnder interferometer. In addition, the variation in the local heat transfer coefficient is evaluated experimentally with respect to the air flow velocity and temperature. Differences within the heat transfer performance between the plates are confirmed and discussed. As a result, the average heat transfer performance is about the same for the heated plate and the cooled plate under all air velocity conditions. This contrasts with the theoretical prediction in the case of low air velocity, the reason considered was that the buoyancy at the 30° leading edge blocked air from flowing across the surface of the plate.展开更多
The temperature-induced complex refractive index（CRI） effect of graphene is demonstrated theoretically and experimentally based on a graphene coated in-fiber MZI（Mach-Zehnder interferometer）. The relationships bet...The temperature-induced complex refractive index（CRI） effect of graphene is demonstrated theoretically and experimentally based on a graphene coated in-fiber MZI（Mach-Zehnder interferometer）. The relationships between real and imaginary parts of the graphene CRI and temperature are obtained through investigating the dip wavelength and intensity of the MZI interference spectrum changing with temperature, respectively. The temperature effect of CRI of the graphene is also analyzed theoretically. Both experimental and theoretical studies show that the real part and imaginary part of the CRI nonlinearly decrease and increase with temperature increasing, respectively. This graphene-coated in-fiber MZI structure also possesses the advantages of easy fabrication, miniaturization, low cost and robustness. It has potential applications in nanomaterial-based optic devices for communication and sensing.展开更多
An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferom...An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.展开更多
We argue that the modification proposed by Li et al. [Chin. Phys. Lett. 32 （2015）050303] to the experiment of Danan et al. [Phys. Rev. Lett. 111 （2013） 240402] does not test the past of the photon as characterized...We argue that the modification proposed by Li et al. [Chin. Phys. Lett. 32 （2015）050303] to the experiment of Danan et al. [Phys. Rev. Lett. 111 （2013） 240402] does not test the past of the photon as characterized by local weak traces. Instead of answering the questions： （i） were the photons in A？ （ii） were the photons in B？ and （iii） were the photons in C？ the proposed experiment measures a degenerate operator answering the questions： （i） were the photons in A？ and （ii） were the photons in B and C together？ A negative answer to the last question does not tell us if photons were present in B or C. On the other hand, a simple variation of the proposal by Li et al. does provide conceptually better evidence for the past of the pre- and post-selected photon, but this evidence will be in agreement with the results of Danan et al.展开更多
On the silicon-on-insulator platform, an ultra compact temperature-insensitive modulator based on a cascaded microring assistant Mach-Zehnder interferometer is proposed and demonstrated with numerical simulation. Acco...On the silicon-on-insulator platform, an ultra compact temperature-insensitive modulator based on a cascaded microring assistant Mach-Zehnder interferometer is proposed and demonstrated with numerical simulation. According to the calculated results, the tolerated variation of ambient temperature can be as high as 134 ℃ while the footprint of such a silicon modulator is only 340 μm2.展开更多
An ideal experiment is designed to determine the past of a particle in the nested Mach-Zehnder interferometer （MZI） by using standard quantum mechanics with quantum non-demolition measurements. We find that when the...An ideal experiment is designed to determine the past of a particle in the nested Mach-Zehnder interferometer （MZI） by using standard quantum mechanics with quantum non-demolition measurements. We find that when the photon reaches the detector, it only follows one arm of the outer interferometer and leaves no trace in the inner MZI. When it goes through the inner MZI, it cannot reach the detector. Our result obtained from the standard quantum mechanics contradicts the statement based on two-state vector formulism, ＇the photon did not enter the （inner） interferometer, the photon never left the interferometer, but it was there＇. Therefore, the statement and also the overlapping claim are incorrect.展开更多
We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass ...We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass both the arms of the MZ interferometer while the idler photons pass one arm only. Interestingly, the probability of the idler photons emerging from any output port still shows a sine oscillation with the two-photon phase difference and it can be characterized only by the indistinguishability of the two-photon amplitudes. We also observe a two-photon interference pattern with a period being equal to the wavelength of the parametric photons instead of the two-photon photonie de Broglie wavelength due to the presence of two-photon phase difference, in particular, with complementary probabilities of finding the two-photon pairs in two output ports. The abundant observations can facilitate a more comprehensive understanding of the two-photon interference.展开更多
To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The...To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The introduction of π phase shifter into FI, dramatically suppresses the dispersion effiect. Then the transmission response remains square-like shape, with low frequency deviation and high extinction ratio. Moreover, the lower frequency deviation is achieved by reducing the dispersion coefficient. For 100GHz-spacing interleaver, the 0.08nm deviation is reduced to 0.02nm by replacing G.652 with G.655.展开更多
The present study delves into the application of investigating quantum state behaviour,particularly focusing on coherent and superposition states.These states,characterized by their remarkable stability and precision,...The present study delves into the application of investigating quantum state behaviour,particularly focusing on coherent and superposition states.These states,characterized by their remarkable stability and precision,have found extensive utility in various domains of quantum mechanics and quantum information processing.Coherent states are valuable for manipulating quantum systems with accuracy.Superposition states allow quantum systems to exist in numerous configurations at the same time,which paves the way for quantum computing’s capacity for parallel processing.The research accentuates the crucial role of quantum error correction(QEC)in ensuring the stability and reliability of quantum information processing systems.Quantum systems are prone to errors from decoherence and environmental noise,making QEC essential for ensuring accurate results by employing the Shor code,an error-correcting code devised by Peter Shor,it becomes feasible to detect and rectify errors that may arise during quantum computations.The Shor code detects and corrects both bit-flip and phase-flip errors,greatly enhancing the robustness of quantum information systems.This research offers insights into the multifaceted utility of MZI(Mach-Zehnder interferometer)and its relevance in the advancement of quantum technology.By integrating QEC with the capabilities of MZI,this study offers a holistic approach to advancing the precision and reliability of quantum technologies.展开更多
We report investigations of three types of silica-based thermo-optic modulating Mach-Zehnder interferometers(MZIs).They are widely used in optical communication and quantum photonics.Three types of MZIs are fabricated...We report investigations of three types of silica-based thermo-optic modulating Mach-Zehnder interferometers(MZIs).They are widely used in optical communication and quantum photonics.Three types of MZIs are fabricated.The waveguide structure and fabrication process are paid special attention.The power consumption is less than 250 mW for all MZIs.The polarization dependent loss(PDL)at the same attenuation using the upper heater is less than that using the lower heater for the three types of MZIs.In addition,it is found that the PDL at the same attenuation increases gradually forπ,2πand 0 phase differences.The measured response time of the three types of MZIs is less than 1.8 ms.展开更多
In this paper, magnetic fluid(MF), a new type of optical functional nanomaterial with interesting optical characteristics under the external magnetic field, is adopted to form a novel fiber-optic magnetic field sensor...In this paper, magnetic fluid(MF), a new type of optical functional nanomaterial with interesting optical characteristics under the external magnetic field, is adopted to form a novel fiber-optic magnetic field sensor. The proposed sensor is based on Mach-Zehnder interferometer (MZI) and has a multimode-singlemode-multimode(MSM) fiber structure. The MSM structure was fabricated by splicing a section of uncoated single mode fiber (SMF) between two short sections of multimode fibers(MMFs) using a fiber fusion splicer. The magnetic field sensing probe was made by inserting the fiberoptic structure in an MF-filled capillary tube. Variations in an external magnetic field is seen to cause changes in the refractive index of MF. This tunable change in the refractive index with magnetic field strengths between 0.6 mT to 21.4 mT produces a shift in the peak position of the wavelength. The shift of the valley wavelength with magnetic field intensity has a good linearity of up to 99.6%. The achieved sensitivity of the proposed magnetic field sensor is 0.123 nm/mT, which is improved by several folds compared with those of most of the other reported MF-based magnetic field sensors. Furthermore, we build the corresponding circuit-based measurement system, and the experimental results show that the voltage change indirectly reflects the change of the external magnetic field strength. Therefore, this provides the potential to fiber-based magnetic field sensing applications.展开更多
An up-tapered Mach-Zehnder interferometer(MZI) is proposed and demonstrated.By applying a modification setting of an existing program of the fusion splicer,two up-tapers are fabricated by pushing both sides of the fib...An up-tapered Mach-Zehnder interferometer(MZI) is proposed and demonstrated.By applying a modification setting of an existing program of the fusion splicer,two up-tapers are fabricated by pushing both sides of the fiber to the middle.It is found that the maximum extinction ratio reaches up to 20 dB.With the fiber length of 6.3-49 cm between the two up-tapers,the free spectral range(FSR) changes from 10.7 nm to 1.3 nm.Besides,the wavelength of maximum extinction ratio shifts to the shorter wavelength in the scope of tens of nanometers,while the elongation changes from 0% to 0.23%.展开更多
An all-fiber temperature and curvature sensor based on Mach-Zehnder interferometer(MZI)was proposed.The MZI was a sandwich structure which is composed of ring-core fiber(RCF),no-core fiber(NCF)and single-mode fiber(SM...An all-fiber temperature and curvature sensor based on Mach-Zehnder interferometer(MZI)was proposed.The MZI was a sandwich structure which is composed of ring-core fiber(RCF),no-core fiber(NCF)and single-mode fiber(SMF).The temperature and curvature can be demodulated by the wavelength shift and the intensity variation of the dips respectively in the transmission spectrum.The measurement results show that the sensitivity of curvature is−7.88 dBm/m^(−1)in the range from 3.0 m^(−1)to 4.2 m^(−1)and the sensitivity of temperature is 53.5 pm/°C in the range from 60°C to 200°C.In addition,the cascaded FBG in the proposed structure,also sensitive to temperature,was used to monitor the fluctuation of temperature.The compact structure,the real-time temperature and the high curvature sensitivity make the sensor have the potential in the field of construction health monitoring and mining safety production.展开更多
Fiber optic Mach Zehnder interferometer(MZI) can be used as wavelength multiplexers and demultiplexers. The △ L and △ directly influence the properties of MZI. To lengthen the △ L can demultiplex much more wavelen...Fiber optic Mach Zehnder interferometer(MZI) can be used as wavelength multiplexers and demultiplexers. The △ L and △ directly influence the properties of MZI. To lengthen the △ L can demultiplex much more wavelengths, but when the △ L is longer, the temperature will influence MZI more seriously. A method to solve this problem is proposed, which enables MZI to work stably. The wavelength distance is 0.8 nm, and the extinction ratio is high.展开更多
The NAND operation at 250 Gbit/s based on quantum dot-semiconductor optical amplifiers (QD-SOAs) is modeled. By solving the rate equations of SOAs in the form of a Mach-Zehnder interferometer (MZI), the performance of...The NAND operation at 250 Gbit/s based on quantum dot-semiconductor optical amplifiers (QD-SOAs) is modeled. By solving the rate equations of SOAs in the form of a Mach-Zehnder interferometer (MZI), the performance of NAND gate is numerically investigated. The model takes the effects of ampli?ed spontaneous emission (ASE) and the input pulse energy on the system's quality factor into account. Results show that NAND gate in QD-SOA-MZI based structure is feasible at 250 Gbit/s with a proper quality factor. The decrease in quality factor is predicted for high spontaneous emission factor (NSP). For an ideal amplifier (NSP = 2), the Q-factor is 17.8 for 30 dB gain.展开更多
基金Supported by the Central Government Guidance on Local Science and Technology Development Funds(2023ZY1023)the Six Talent Peaks Project in Jiangsu Province(KTHY-052).
文摘A novel near-infrared all-fiber mode monitor based on a mini-two-path Mach-Zehnder interferometer(MTP-MZI)is proposed.The MTP-MZI mode monitor is created by fusing a section of(no-core fiber,NCF)and a(single-mode fiber,SMF)together with an optical fiber fusion splicer,establishing two distinct centimeter-level optical transmission paths.Since the high-order modes in NCF transmit near-infrared light more sensitively to curvature-induced energy leakage than the fundamental mode in SMF,the near-infrared high-order mode light leaks out of NCF when the curvature changes,causing the MTP-MZI transmission spectrum to change.By ana⁃lyzing the relationship between the curvature,transmission spectrum,and spatial frequency spectrum,the modes involved in the interference can be studied,thereby revealing the mode transmission characteristics of near-infra⁃red light in optical fibers.In the verification experiments,higher-order modes were excited by inserting a novel hollow-core fiber(HCF)into the MTP-MZI.When the curvature of the MTP-MZI changes,the near-infrared light high-order mode introduced into the device leaks out,causing the transmission spectrum to return to its origi⁃nal state before bending and before the HCF was spliced.The experimental results demonstrate that the MTP-MZI mode monitor can monitor the fiber modes introduced from the external environment,providing both theoretical and experimental foundations for near-infrared all-fiber mode monitoring in optical information systems.
文摘A polarization-maintaining （PM） fiber Mach-Zehnder （MZ） interferometer has been established to measure the EO effect of very thin film materials with optical anisotropy. Unlike a common MZ interferometer, all the components are connected via polarization-maintaining fibers. At the same time, a polarized DFB laser with a maximum power output of 10mW is adopted as the light source to induce a large extinction ratio. Here,we take it to determine the electro-optical coefficients of a very thin superlattice structure with GaAs, KTP, and GaN as comparative samples. The measured EO coefficients show good comparability with the others.
基金Supported by the National Basic Research Program of China under Grant No 2013CB632704the National Natural Science Foundation of China under Grant No 11434017
文摘Many delayed-choice experiments based on Mach-Zehnder interferometers （MZI） have been considered and made to address the fundamental problem of wave-particle duality. Conventional wisdom long holds that by inserting or removing the second beam splitter （BS2） in a controllable way, microscopic particles （photons, electrons, etc.） transporting within the MZI can lie in the quantum superposition of the wave and particle state as ψ= aw ψ wave ＋ ap ψ particle. Here we present an alternative interpretation to these delayed-choice experiments. We notice that as the BS2 is purely classical, the inserting and removing operation of the BS2 imposes a time- modulated Hamiltonian H mod （t） = a（t）Hin ＋ b（t）Hout, instead of a quantum superposition of H in and Hour as H = awHin ＋ apHout, to act upon the incident wave function. Solution of this quantum scattering problem, rather than the long held quantum eigen-problem yields a synchronically time-modulated output wave function as ψ mod （t） = a（t） ψ wave ＋b（t） ψ particle, instead of the stationary quantum superposition state ψ = aw ψ wave ＋ ap ψ particle. As a result, the probability of particle output from the MZI behaves as if they are in the superposition of the wave and particle state when many events over time accumulation are counted and averaged. We expect that these elementary but insightful analyses will shed a new light on exploring basic physics beyond the long-held wisdom of wave-particle duality and the principle of complementarity.
基金Project supported by the Innovation Program of Education Commission of Shanghai Municipality (Grant No.10YZ19)the Shanghai Leading Academic Discipline Project (Grant No.S30108)the Shanghai Key Laboratory of Specialty Fiber Optics and Optical Access Networks (Grant No.SKLSFO200903)
文摘A distributed optical fiber disturbance detection system consisted of a Sagnac interferometer and a Mach-Zehnder interferometer is demonstrated. Two interferometers outputs are connected to an electric band-pass filter via a detector respectively. The central frequencies of the two filters are selected adaptively according to the disturbance frequency. The disturbance frequency is obtained by either frequency spectrum of the two interferometers outputs. An alarm is given out only when the Sagnac interferometer output is changed. A disturbance position is determined by calculating a time difference with a cross-correlation method between the filter output connected to the Sagnac interferometer and derivative of the filter output connected to the Mach-Zehnder interferometer. The frequency spectrum, derivative and cross-correlation are obtained by a signal processing system. Theory analysis and simulation results are presented. They show that the system structure and location method are effective, accurate, and immune to environmental variations.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61077006,60727004,and 61077060the China National Petroleum Corporation Science and Technology Development Projects under Grant No 2014B-4012the Science Research Plan Projects of Shaanxi Education Department under Grant No 14JK1580
文摘An in-fiber Mach-Zehnder interferometer for strain measurement is proposed and experimentally demonstrated. The sensor consists of a taper followed by a short section of a multi-mode fiber （MMF） and a dispersion com- pensating fiber （DCF）, which is sandwiched between two single mode fibers （SMFs）. The taper is used as a fiber coupler to excite cladding modes in the SMF, and these cladding modes transmit within the MMF and the DCF. The core mode and the cladding modes interfere in the DCF SMF fusion point to form intermodal interference. A well-defined interference spectrum is obtained in the experiment. Selected interference dips are used to measure the strain changes. The experimental results show that this device is sensitive to strain with the wavelength-referenced sensitivity of 2.6 pm/με and the power-referenced sensitivity of 0. 0027 dB/με, respectively.
文摘This study focuses on the experimental measurements of the heat transfer coefficient over a flat plate with a 30° leading edge. Under forced convection by a hot/cold air and flow over a cooled/heated flat plate, the thermal boundary layer and its thickness are quantitatively visualized and measured using a Mach-Zehnder interferometer. In addition, the variation in the local heat transfer coefficient is evaluated experimentally with respect to the air flow velocity and temperature. Differences within the heat transfer performance between the plates are confirmed and discussed. As a result, the average heat transfer performance is about the same for the heated plate and the cooled plate under all air velocity conditions. This contrasts with the theoretical prediction in the case of low air velocity, the reason considered was that the buoyancy at the 30° leading edge blocked air from flowing across the surface of the plate.
基金Project supported by the Shandong Provincial Natural Science Foundation of China(Grant Nos.ZR2009AM017 and ZR2013FM019)the National Postdoctoral Project of China(Grant Nos.200902574 and 20080441150)+2 种基金the Shandong Provincial Education Department Foundation of China(Grant No.J06P14)the Opening Foundation of State Key Lab of Minning Disaster Prevention and Control Co-founded by Shandong Provincethe Ministry of Science and Technology of China(Grant No.MDPC201602)
文摘The temperature-induced complex refractive index（CRI） effect of graphene is demonstrated theoretically and experimentally based on a graphene coated in-fiber MZI（Mach-Zehnder interferometer）. The relationships between real and imaginary parts of the graphene CRI and temperature are obtained through investigating the dip wavelength and intensity of the MZI interference spectrum changing with temperature, respectively. The temperature effect of CRI of the graphene is also analyzed theoretically. Both experimental and theoretical studies show that the real part and imaginary part of the CRI nonlinearly decrease and increase with temperature increasing, respectively. This graphene-coated in-fiber MZI structure also possesses the advantages of easy fabrication, miniaturization, low cost and robustness. It has potential applications in nanomaterial-based optic devices for communication and sensing.
基金supported by the National Natural Science Foundation of China (No. 40774067)the Applied Basic Research Program of Sichuan Province, China (No. 07JY029-135)
文摘An investigation of the properties ofa LiNbO3 photoelastic waveguide via the acceleration-induced effect is presented. A novel three-component hybrid-integrated optical accelerometer based on a Mach-Zehnder interferometer with a LiNbO3 photoelastic waveguide has been designed, which is capable of detecting seismic acceleration in high-accuracy seismic exploration. The Mach-Zehnder interferometer was successfully fabricated and a lighting test used to check its quality. The frequency response characteristic of the accelerometer was measured2 The accelerometer with a resonant frequency of 3549 Hz was demonstrated to show good linear frequency responding characteristics in the range of 100-3000 Hz. The accelerometer also shows good stability and consistency. Experimental results indicate that the outputs of the on- and cross-axis are 147 and 21.3 mV, respectively.
基金Supported by the German-Israeli Foundation for Scientific Research and Development under Grant No I-1275-303.14
文摘We argue that the modification proposed by Li et al. [Chin. Phys. Lett. 32 （2015）050303] to the experiment of Danan et al. [Phys. Rev. Lett. 111 （2013） 240402] does not test the past of the photon as characterized by local weak traces. Instead of answering the questions： （i） were the photons in A？ （ii） were the photons in B？ and （iii） were the photons in C？ the proposed experiment measures a degenerate operator answering the questions： （i） were the photons in A？ and （ii） were the photons in B and C together？ A negative answer to the last question does not tell us if photons were present in B or C. On the other hand, a simple variation of the proposal by Li et al. does provide conceptually better evidence for the past of the pre- and post-selected photon, but this evidence will be in agreement with the results of Danan et al.
基金Project supported by the National Basic Research Program of China(Grant Nos.2011CBA00608,2011CBA00303,2011CB301803, and 2010CB327405)the National Natural Science Foundation of China(Grant Nos.61036011 and 61036010)the Project of Science and Technology from the Communication Information Security Control Laboratory
文摘On the silicon-on-insulator platform, an ultra compact temperature-insensitive modulator based on a cascaded microring assistant Mach-Zehnder interferometer is proposed and demonstrated with numerical simulation. According to the calculated results, the tolerated variation of ambient temperature can be as high as 134 ℃ while the footprint of such a silicon modulator is only 340 μm2.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CB922203 and 2012CB921603the National Natural Science Foundation of China under Grant Nos 1174026 and U1330203
文摘An ideal experiment is designed to determine the past of a particle in the nested Mach-Zehnder interferometer （MZI） by using standard quantum mechanics with quantum non-demolition measurements. We find that when the photon reaches the detector, it only follows one arm of the outer interferometer and leaves no trace in the inner MZI. When it goes through the inner MZI, it cannot reach the detector. Our result obtained from the standard quantum mechanics contradicts the statement based on two-state vector formulism, ＇the photon did not enter the （inner） interferometer, the photon never left the interferometer, but it was there＇. Therefore, the statement and also the overlapping claim are incorrect.
基金Supported by the National Key R&D Program of China under Grant Nos 2017YFA0303800 and 2017YFA0303700the National Natural Science Foundation of China under Grant Nos 11534006,11774183 and 11674184+1 种基金the Natural Science Foundation of Tianjin under Grant No 16JCZDJC31300the Collaborative Innovation Center of Extreme Optics
文摘We present a two-photon interference experiment in a modified Mach-Zehnder （MZ） interferometer in which two Hong-Ou-Mandel effects occur in tandem and construct superposed two-photon states. The signal photons pass both the arms of the MZ interferometer while the idler photons pass one arm only. Interestingly, the probability of the idler photons emerging from any output port still shows a sine oscillation with the two-photon phase difference and it can be characterized only by the indistinguishability of the two-photon amplitudes. We also observe a two-photon interference pattern with a period being equal to the wavelength of the parametric photons instead of the two-photon photonie de Broglie wavelength due to the presence of two-photon phase difference, in particular, with complementary probabilities of finding the two-photon pairs in two output ports. The abundant observations can facilitate a more comprehensive understanding of the two-photon interference.
基金Supported by the National Natural Science Foundation of China （No.10174057, 90201011） and the Key Project of Chinese Ministry of Education （No.105148）.
文摘To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The introduction of π phase shifter into FI, dramatically suppresses the dispersion effiect. Then the transmission response remains square-like shape, with low frequency deviation and high extinction ratio. Moreover, the lower frequency deviation is achieved by reducing the dispersion coefficient. For 100GHz-spacing interleaver, the 0.08nm deviation is reduced to 0.02nm by replacing G.652 with G.655.
文摘The present study delves into the application of investigating quantum state behaviour,particularly focusing on coherent and superposition states.These states,characterized by their remarkable stability and precision,have found extensive utility in various domains of quantum mechanics and quantum information processing.Coherent states are valuable for manipulating quantum systems with accuracy.Superposition states allow quantum systems to exist in numerous configurations at the same time,which paves the way for quantum computing’s capacity for parallel processing.The research accentuates the crucial role of quantum error correction(QEC)in ensuring the stability and reliability of quantum information processing systems.Quantum systems are prone to errors from decoherence and environmental noise,making QEC essential for ensuring accurate results by employing the Shor code,an error-correcting code devised by Peter Shor,it becomes feasible to detect and rectify errors that may arise during quantum computations.The Shor code detects and corrects both bit-flip and phase-flip errors,greatly enhancing the robustness of quantum information systems.This research offers insights into the multifaceted utility of MZI(Mach-Zehnder interferometer)and its relevance in the advancement of quantum technology.By integrating QEC with the capabilities of MZI,this study offers a holistic approach to advancing the precision and reliability of quantum technologies.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016902)the National Natural Science Foundation of China(Nos.61435013 and 61405188)the K.C.Wong Education Foundation
文摘We report investigations of three types of silica-based thermo-optic modulating Mach-Zehnder interferometers(MZIs).They are widely used in optical communication and quantum photonics.Three types of MZIs are fabricated.The waveguide structure and fabrication process are paid special attention.The power consumption is less than 250 mW for all MZIs.The polarization dependent loss(PDL)at the same attenuation using the upper heater is less than that using the lower heater for the three types of MZIs.In addition,it is found that the PDL at the same attenuation increases gradually forπ,2πand 0 phase differences.The measured response time of the three types of MZIs is less than 1.8 ms.
基金supported by the National Natural Science Foundation of China(No.11274278)
文摘In this paper, magnetic fluid(MF), a new type of optical functional nanomaterial with interesting optical characteristics under the external magnetic field, is adopted to form a novel fiber-optic magnetic field sensor. The proposed sensor is based on Mach-Zehnder interferometer (MZI) and has a multimode-singlemode-multimode(MSM) fiber structure. The MSM structure was fabricated by splicing a section of uncoated single mode fiber (SMF) between two short sections of multimode fibers(MMFs) using a fiber fusion splicer. The magnetic field sensing probe was made by inserting the fiberoptic structure in an MF-filled capillary tube. Variations in an external magnetic field is seen to cause changes in the refractive index of MF. This tunable change in the refractive index with magnetic field strengths between 0.6 mT to 21.4 mT produces a shift in the peak position of the wavelength. The shift of the valley wavelength with magnetic field intensity has a good linearity of up to 99.6%. The achieved sensitivity of the proposed magnetic field sensor is 0.123 nm/mT, which is improved by several folds compared with those of most of the other reported MF-based magnetic field sensors. Furthermore, we build the corresponding circuit-based measurement system, and the experimental results show that the voltage change indirectly reflects the change of the external magnetic field strength. Therefore, this provides the potential to fiber-based magnetic field sensing applications.
基金supported by the National Natural Science Foundation of China(Nos.61177069,61275076 and 61275092)"973"Program(No.2010CB328206)
文摘An up-tapered Mach-Zehnder interferometer(MZI) is proposed and demonstrated.By applying a modification setting of an existing program of the fusion splicer,two up-tapers are fabricated by pushing both sides of the fiber to the middle.It is found that the maximum extinction ratio reaches up to 20 dB.With the fiber length of 6.3-49 cm between the two up-tapers,the free spectral range(FSR) changes from 10.7 nm to 1.3 nm.Besides,the wavelength of maximum extinction ratio shifts to the shorter wavelength in the scope of tens of nanometers,while the elongation changes from 0% to 0.23%.
基金supported by the National Natural Science Foundation of China (No.62175055)the Natural Science Foundation of Handan University (No.XZ2022408)
文摘An all-fiber temperature and curvature sensor based on Mach-Zehnder interferometer(MZI)was proposed.The MZI was a sandwich structure which is composed of ring-core fiber(RCF),no-core fiber(NCF)and single-mode fiber(SMF).The temperature and curvature can be demodulated by the wavelength shift and the intensity variation of the dips respectively in the transmission spectrum.The measurement results show that the sensitivity of curvature is−7.88 dBm/m^(−1)in the range from 3.0 m^(−1)to 4.2 m^(−1)and the sensitivity of temperature is 53.5 pm/°C in the range from 60°C to 200°C.In addition,the cascaded FBG in the proposed structure,also sensitive to temperature,was used to monitor the fluctuation of temperature.The compact structure,the real-time temperature and the high curvature sensitivity make the sensor have the potential in the field of construction health monitoring and mining safety production.
文摘Fiber optic Mach Zehnder interferometer(MZI) can be used as wavelength multiplexers and demultiplexers. The △ L and △ directly influence the properties of MZI. To lengthen the △ L can demultiplex much more wavelengths, but when the △ L is longer, the temperature will influence MZI more seriously. A method to solve this problem is proposed, which enables MZI to work stably. The wavelength distance is 0.8 nm, and the extinction ratio is high.
文摘The NAND operation at 250 Gbit/s based on quantum dot-semiconductor optical amplifiers (QD-SOAs) is modeled. By solving the rate equations of SOAs in the form of a Mach-Zehnder interferometer (MZI), the performance of NAND gate is numerically investigated. The model takes the effects of ampli?ed spontaneous emission (ASE) and the input pulse energy on the system's quality factor into account. Results show that NAND gate in QD-SOA-MZI based structure is feasible at 250 Gbit/s with a proper quality factor. The decrease in quality factor is predicted for high spontaneous emission factor (NSP). For an ideal amplifier (NSP = 2), the Q-factor is 17.8 for 30 dB gain.
