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
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
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
In this paper, the author analyzes characteristics and extracting method of interference signal of the distributed optical fiber sensing. In the distributed optical fiber sensing, realizing alarm and positioning funct...In this paper, the author analyzes characteristics and extracting method of interference signal of the distributed optical fiber sensing. In the distributed optical fiber sensing, realizing alarm and positioning function only through the cross-correlation operation will increase the load of the system, can make misinformation rate of the system be improved greatly. Therefore, before the localization algorithm, adding a interference signal feature recognition is very necessary, can reduce unnecessary operation loss and reduce the load of the system, also reducing the number of the false positives.展开更多
In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveg...In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveguide widths in a period,a reflection channel with a large bandwidth is firstly achieved.Besides,the Mach-Zehnder interference(MZI)effect arises by shifting the gratings away from the waveguide center.Owing to different optical paths with unequal indices on both sides of the grating,a narrow MZI band gap will be obtained.It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other,and their wavelengths can be manipulated by the period and the grating length,respectively.Additionally,we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period.The performances are investigated by finite-difference time-domain(FDTD)simulations.In the index range of 1.33–1.36,the maximum sensitivity for the structure is as high as 1500 nm/RIU,and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.展开更多
A new in-line Mach-Zehnder interferometer (MZI) sensor consisting of a stub of multi-mode fiber and an up-taper was proposed and demonstrated. Temperature measurement can be carried out by detecting wavelength shift...A new in-line Mach-Zehnder interferometer (MZI) sensor consisting of a stub of multi-mode fiber and an up-taper was proposed and demonstrated. Temperature measurement can be carried out by detecting wavelength shift. Dependency of sensitivity on interferometer length and dip wavelength was discussed. Experimental results showed a maximum temperature sensitivity of 113.6pm/℃ can be achieved, which is superior to most fiber temperature sensors based on in-line MZIs within the range from 20℃ to 80℃, also a good mechanical strength can be obtained. The proposed sensor is a good candidate for temperature measurement, due to the advantages of simple structure, easy fabrication, cost- effective and high sensitivity.展开更多
Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc....Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc. The nonlinear correction term is basically responsible for the optical switches. Mach-Zehnder inter- ferometer (MZI) is a well-known arrangement for determining the above correction term, but there are some major problems for finding out the term by MZI. We propose a new method of finding the nonlinear correction term as well as the second order nonlinear susceptibility of the materials by using a modified MZI system. This method may be used to find out the above parameters for any unknown nonlinear material.展开更多
In this paper, we derive the bright and dark photon number states for spatial interference of two or more light beams and succeed in the explanation of Young's interference experiment, and also achieve a better co...In this paper, we derive the bright and dark photon number states for spatial interference of two or more light beams and succeed in the explanation of Young's interference experiment, and also achieve a better comprehension of the well known comment of Dirac 'each photon only interferences with itself'. Prom the fully quantum point of view, the origin of the interference fringes consists in the mode transformation and the detection of double-slit states.展开更多
The present paper has mainly the aim to formulate a quantum neurological model of brain dynamics during perception and cognition of ambiguous figures here including the case of the Dalmatian dog. First of all, we summ...The present paper has mainly the aim to formulate a quantum neurological model of brain dynamics during perception and cognition of ambiguous figures here including the case of the Dalmatian dog. First of all, we summarize our previous experimental and theoretical studies, evidencing as the basic conceptual foundations of quantum mechanics enter in a decisive manner in explaining the basic functions of brain dynamics at perceptive and cognitive level and at the level of our consciousness. This is done in detail in Sections 2 and 3 where we discuss also the role of the so called quantum interference effect and we include here the results of an our recent experiment confirming the role of quantum theory and of its quantum interference effect also at perceptive-cognitive and awareness levels. In Section 4, following our previous study, we consider the so called Mach-Zehnder interferometer. It is a physical device that is employed in quantum mechanical experiments in order to analyze such quantum interference effect. Soon after the discussion of this device, we proceed with the elaboration of a detailed quantum neurological model in the sense that we consider the brain regions identified in V1;V2/V3/V4 and A20 and we obtain that they may behave just as the beam splitters involved in the Mach-Zehnder quantum mechanical interferometer. In this manner, we formulate a model of V1;V2/V3/V4, A20 brain dynamics as a Mach-Zehnder interferometer and such model delineates a proposed neurological mechanism explaining perception-cognition and awareness in humans under the input of ambiguous figures and in the particular case of the Dalmatian dog.展开更多
A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Let...A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform (FFT) spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference (DMI) spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT (IFFT). Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU (RI unit) and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.展开更多
The production of maxima and minima by the superposition of two or more light signals provides fundamental support for the wave nature of light. This result is based on the study of wave interference phenomena which r...The production of maxima and minima by the superposition of two or more light signals provides fundamental support for the wave nature of light. This result is based on the study of wave interference phenomena which remains the only approach to explain the production of those maxima and minima. In a system that is prepared to work with only one photon at a time, any detector can signal only one or zero. In 1986, a rigorously controlled experiment was designed by Grangier, G. Roger, and A. Aspect, [Europhys Lett. 1(4), p. 173, 1986] that guaranteed a single-photon beam. The explanation of the experimental results implied the interference of the wave function of a single-photon with itself. Thus, the explanation of interference that is accepted for an ensemble of photons was assumed to be valid for a single photon. In this study, we prepare a Mach-Zehnder interferometer using the same type of beam splitters used by Grangier et al. to test the assumption mentioned above. Our results allow us to explain the results of Grangier et al. because of the interaction between light and the beam splitters. Our results also verify that their wave interpretation of the results is not valid. Here, we present the essential findings of the extensive experimental evidence that supports our ideas.展开更多
This letter introduces a simple model to explain the Diffraction and Interference of Light. It was created using only a corpuscular point of view. The mean concept of the model introduced in this paper is that light h...This letter introduces a simple model to explain the Diffraction and Interference of Light. It was created using only a corpuscular point of view. The mean concept of the model introduced in this paper is that light has two independent states of polarization that oscillate with equal frequencies but with a π/2 difference of phase. This model allows the author to determine the intensity of light at any point after it exceeds no edge or any number of them.展开更多
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 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In this paper, the author analyzes characteristics and extracting method of interference signal of the distributed optical fiber sensing. In the distributed optical fiber sensing, realizing alarm and positioning function only through the cross-correlation operation will increase the load of the system, can make misinformation rate of the system be improved greatly. Therefore, before the localization algorithm, adding a interference signal feature recognition is very necessary, can reduce unnecessary operation loss and reduce the load of the system, also reducing the number of the false positives.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFB1803505)the National Natural Science Foundation of China(Grant Nos.U2001601,62175039,and 61925501)+3 种基金the Science and Technology Project of Guangzhou(Grant No.201904010243)Major Special Projects in Guangdong Province(Grant No.2018B010114002)the Engineering Research Center of Digital Imaging and Display,Ministry of Education,Soochow University(Grant No.SDGC2133)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams.
文摘In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveguide widths in a period,a reflection channel with a large bandwidth is firstly achieved.Besides,the Mach-Zehnder interference(MZI)effect arises by shifting the gratings away from the waveguide center.Owing to different optical paths with unequal indices on both sides of the grating,a narrow MZI band gap will be obtained.It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other,and their wavelengths can be manipulated by the period and the grating length,respectively.Additionally,we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period.The performances are investigated by finite-difference time-domain(FDTD)simulations.In the index range of 1.33–1.36,the maximum sensitivity for the structure is as high as 1500 nm/RIU,and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Nos. 61275083 and 61290315) and the Fundamental Research Funds for the Central Universities (HUST: No. 2014CG002).
文摘A new in-line Mach-Zehnder interferometer (MZI) sensor consisting of a stub of multi-mode fiber and an up-taper was proposed and demonstrated. Temperature measurement can be carried out by detecting wavelength shift. Dependency of sensitivity on interferometer length and dip wavelength was discussed. Experimental results showed a maximum temperature sensitivity of 113.6pm/℃ can be achieved, which is superior to most fiber temperature sensors based on in-line MZIs within the range from 20℃ to 80℃, also a good mechanical strength can be obtained. The proposed sensor is a good candidate for temperature measurement, due to the advantages of simple structure, easy fabrication, cost- effective and high sensitivity.
文摘Nonlinear materials have been well established as photo refractive switching material. Important applica- tions of isotropic nonlinear materials are seen in self-focusing, defocusing phenomena, switching systems, etc. The nonlinear correction term is basically responsible for the optical switches. Mach-Zehnder inter- ferometer (MZI) is a well-known arrangement for determining the above correction term, but there are some major problems for finding out the term by MZI. We propose a new method of finding the nonlinear correction term as well as the second order nonlinear susceptibility of the materials by using a modified MZI system. This method may be used to find out the above parameters for any unknown nonlinear material.
文摘In this paper, we derive the bright and dark photon number states for spatial interference of two or more light beams and succeed in the explanation of Young's interference experiment, and also achieve a better comprehension of the well known comment of Dirac 'each photon only interferences with itself'. Prom the fully quantum point of view, the origin of the interference fringes consists in the mode transformation and the detection of double-slit states.
文摘The present paper has mainly the aim to formulate a quantum neurological model of brain dynamics during perception and cognition of ambiguous figures here including the case of the Dalmatian dog. First of all, we summarize our previous experimental and theoretical studies, evidencing as the basic conceptual foundations of quantum mechanics enter in a decisive manner in explaining the basic functions of brain dynamics at perceptive and cognitive level and at the level of our consciousness. This is done in detail in Sections 2 and 3 where we discuss also the role of the so called quantum interference effect and we include here the results of an our recent experiment confirming the role of quantum theory and of its quantum interference effect also at perceptive-cognitive and awareness levels. In Section 4, following our previous study, we consider the so called Mach-Zehnder interferometer. It is a physical device that is employed in quantum mechanical experiments in order to analyze such quantum interference effect. Soon after the discussion of this device, we proceed with the elaboration of a detailed quantum neurological model in the sense that we consider the brain regions identified in V1;V2/V3/V4 and A20 and we obtain that they may behave just as the beam splitters involved in the Mach-Zehnder quantum mechanical interferometer. In this manner, we formulate a model of V1;V2/V3/V4, A20 brain dynamics as a Mach-Zehnder interferometer and such model delineates a proposed neurological mechanism explaining perception-cognition and awareness in humans under the input of ambiguous figures and in the particular case of the Dalmatian dog.
基金supported by the National Natural Science Foundation of China(Nos.61327012 and 61275088)the Research Foundation of Education Bureau of Shaanxi Province,China(No.14JS073)+2 种基金the Youth Science and Technology Innovation Fund of Xi’an Shiyou University(No.2014QN005)the Excellent MA Theses Fund of Xi’an Shiyou University(No.2014yp130816)the Graduate Student Innovation Fund(No.2014cx130842)
文摘A Fourier analysis applied to the Mach-Zehnder interferometer (MZI) transmission spectrum for simultaneous refractive index (RI) and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform (FFT) spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference (DMI) spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT (IFFT). Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU (RI unit) and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.
文摘The production of maxima and minima by the superposition of two or more light signals provides fundamental support for the wave nature of light. This result is based on the study of wave interference phenomena which remains the only approach to explain the production of those maxima and minima. In a system that is prepared to work with only one photon at a time, any detector can signal only one or zero. In 1986, a rigorously controlled experiment was designed by Grangier, G. Roger, and A. Aspect, [Europhys Lett. 1(4), p. 173, 1986] that guaranteed a single-photon beam. The explanation of the experimental results implied the interference of the wave function of a single-photon with itself. Thus, the explanation of interference that is accepted for an ensemble of photons was assumed to be valid for a single photon. In this study, we prepare a Mach-Zehnder interferometer using the same type of beam splitters used by Grangier et al. to test the assumption mentioned above. Our results allow us to explain the results of Grangier et al. because of the interaction between light and the beam splitters. Our results also verify that their wave interpretation of the results is not valid. Here, we present the essential findings of the extensive experimental evidence that supports our ideas.
文摘This letter introduces a simple model to explain the Diffraction and Interference of Light. It was created using only a corpuscular point of view. The mean concept of the model introduced in this paper is that light has two independent states of polarization that oscillate with equal frequencies but with a π/2 difference of phase. This model allows the author to determine the intensity of light at any point after it exceeds no edge or any number of them.