Journals >Chinese Journal of Quantum Electronics
Contents
2005
Volume: 22 Issue 2
34 Article(s)
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Research Article
Review of the progress of T-ray imaging
[in Chinese], [in Chinese], and [in Chinese]
We present an overview of recent progress of T-ray imaging. Compared with microwave, X-ray imaging and NMR (nuclear magnetic resonance), T-ray imaging can give us not only the density picture but also the phase information within the frequency domain. The unique rotational, vibrational and translational responses of maWe present an overview of recent progress of T-ray imaging. Compared with microwave, X-ray imaging and NMR (nuclear magnetic resonance), T-ray imaging can give us not only the density picture but also the phase information within the frequency domain. The unique rotational, vibrational and translational responses of materials (molecular, radicals and ions) within the THz range provide information that is generally absent in optical, X-ray and NMR images.The important characteristic of T-ray is that it has potential to detect the nature of low energy processes in physics, chemistry and biomedicine without the ionization. T-rays can also easily penetrate and image inside most dielectric materials, which make it a useful and complementary imaging source..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 129 (2005)
Interaction between femtosecond laser and matters of crystal and glass
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Many new phenomena of the interaction between femtosecond laser and glass or crystal including photo-induced refractive index changes, photo induced reduction of rare-earth ion, photo induced micro-crystallization of glass, photo stimulated luminescence and long-lasting phosphorescence and so on were concluded. MeanwhiMany new phenomena of the interaction between femtosecond laser and glass or crystal including photo-induced refractive index changes, photo induced reduction of rare-earth ion, photo induced micro-crystallization of glass, photo stimulated luminescence and long-lasting phosphorescence and so on were concluded. Meanwhile, the potential application was analyzed. In the end, the tendencies of the research of the interaction between femtosecond and other materials were discussed. And the new means that could be used when studying on femtosecond laser and crystals were indicated..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 135 (2005)
Microhollow cathode discharge and excimer light source
[in Chinese], and [in Chinese]
Microhollow cathode discharge (MHCD) is a novel, nonequilibrium, high-pressure, direct current glow discharge. An overview of the research progress on the foundational theory of the MHCD was presented. The excimer radiation from the MHCD is discussed in particular, and then discharge mode (dc discharge, pulse dc dischaMicrohollow cathode discharge (MHCD) is a novel, nonequilibrium, high-pressure, direct current glow discharge. An overview of the research progress on the foundational theory of the MHCD was presented. The excimer radiation from the MHCD is discussed in particular, and then discharge mode (dc discharge, pulse dc discharge, RF discharge) effect to the intensity and the efficiency of excimer radiation is elucidated. The operation way (operation in series, operation in parallel) of the MHCD effect to excimer radiation is also discussed finally..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 142 (2005)
Development of large aperture diffractive optical element for super-wide focal-spot beam shaping
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Large aperture diffractive optical elements (DOE) for quasi-annular beam shaping are development. Improved hybrid algorithms including self-iterative algorithm. Quasi-Gradient Descent algorithm and Fourier filtration have been used to design such DOE to form a 650 μm-diameter focal spot in uniform illumination. HolloweLarge aperture diffractive optical elements (DOE) for quasi-annular beam shaping are development. Improved hybrid algorithms including self-iterative algorithm. Quasi-Gradient Descent algorithm and Fourier filtration have been used to design such DOE to form a 650 μm-diameter focal spot in uniform illumination. Hollowed-out mask and ion beam etching system are developed to fabricate the DOE. The performance of the DOE is experimentally studied with 1.064 μm pulsed laser. Wide focal spot with the corresponding size and sharp edge but great modulation are obtained even with large deviation from focus distance. The theoretical analysis with experiment conditions shows that the technical error may be the main reason for the modulation..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 150 (2005)
Comparison of local statistic filtering on speckle of remote sensing image
[in Chinese], and [in Chinese]
The principles of two kinds of typical local statistic algorithm on speckle smoothing, which are named Kuan and σ filtering respectively, are analyzed. Then the smoothing features are compared by doing experiments on real laser remote sensing image. The results indicate that Kuan algorithm has better adaptive ability aThe principles of two kinds of typical local statistic algorithm on speckle smoothing, which are named Kuan and σ filtering respectively, are analyzed. Then the smoothing features are compared by doing experiments on real laser remote sensing image. The results indicate that Kuan algorithm has better adaptive ability and σ filtering is more simple and more efficient..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 155 (2005)
Image fusion method based on region and wavelet transform
[in Chinese], and [in Chinese]
A multi-focus image fusion method based on region of image and multi-resolution of wavelet transform is presented. First, images involved in fusion are decomposed into pyramids. Then the approximation of each layer of the pyramids is segmented into regions to produce a Labeling image by using the method "clusterinA multi-focus image fusion method based on region of image and multi-resolution of wavelet transform is presented. First, images involved in fusion are decomposed into pyramids. Then the approximation of each layer of the pyramids is segmented into regions to produce a Labeling image by using the method "clustering region pixels" . In the Labeling image, each region is corresponding to an object and the same value is given for the pixel of the region. Different region has different value. Secondly, a binary decision map of each layer of the pyramids is produced by means of Labeling image and the rule of selecting the pixel that the region energy is big. Each layer of the pyramid has a binary decision map. Finally, the fused image is reconstructed. The method's performance was evaluated by using error of mean square root. The experiment results show that it has good effective. The performance is better than the performance of the fusion method based on window and the fusion method proposed in the literature [3].
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 159 (2005)
Wavenumber correction in the information processing for FTIR
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Compared with traditional interferometers, refractive scanning interferometer has many notable characteristics, such as high stability and luminous flux. For this kind of interferometer, the change of its optical path is cause by the movement of the optical wedge, and the optical path difference is related to the wavelCompared with traditional interferometers, refractive scanning interferometer has many notable characteristics, such as high stability and luminous flux. For this kind of interferometer, the change of its optical path is cause by the movement of the optical wedge, and the optical path difference is related to the wavelength of the incident light. The wavenumber correction technique adopted solves this problem well with high precision..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 165 (2005)
Detection of weak fluorescence signal in the chlorophyll fluorometer
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The physical mechanism of the chlorophyll fluorometer is simply introduced ,and the electric circuit design for the conversion from weak fluorescence signal to voltage signal with high signal-to-noise ratio is described in detail.The physical mechanism of the chlorophyll fluorometer is simply introduced ,and the electric circuit design for the conversion from weak fluorescence signal to voltage signal with high signal-to-noise ratio is described in detail..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 169 (2005)
Measurement of femtosecond laser pulses with third order correlation technique
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A third-order correlator is built based on the technique of cross-correlation between the fundamental and second harmonic waves of femtosecond lasers. Using this correlator, the contrast ratio of femtosecond (fs) laser pulses from a typical Ti:Sapphire laser is measured. The measurements show detail features of the fs A third-order correlator is built based on the technique of cross-correlation between the fundamental and second harmonic waves of femtosecond lasers. Using this correlator, the contrast ratio of femtosecond (fs) laser pulses from a typical Ti:Sapphire laser is measured. The measurements show detail features of the fs laser pulses. This also provide an effective way to meansure the contrast ratio of amplified fs laser pulses..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 173 (2005)
Frequency stabilization for Ti:sapphire laser with Doppler-broadened Zeeman spectra
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
We have demonstrated a robust and easy frequency stabilization method for Ti:sapphire laser, using Doppler-broadened Zeeman spectrum. In this method, only very weak laser output power (<1 mW) is required, and the experimental setup is relatively simple. A long-time frequency stability of less than 1 MHz/h is achieveWe have demonstrated a robust and easy frequency stabilization method for Ti:sapphire laser, using Doppler-broadened Zeeman spectrum. In this method, only very weak laser output power (<1 mW) is required, and the experimental setup is relatively simple. A long-time frequency stability of less than 1 MHz/h is achieved. In addition, the stability is not affected directly by the laser output power fluctuation and the frequency locking point could be set arbitrarily in the Doppler-broadened spectral range..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 177 (2005)
Compact and tunable diode laser with external grating feedback
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
In configurations with diffraction grating in Littrow mount, putting a grating and a mirror on the plane which can be rotated, and letting the rotating axis of the plane doubling with the cross line between the grating and the mirror, we develop a compact and tunable light source. There is not any position change of ouIn configurations with diffraction grating in Littrow mount, putting a grating and a mirror on the plane which can be rotated, and letting the rotating axis of the plane doubling with the cross line between the grating and the mirror, we develop a compact and tunable light source. There is not any position change of output light beam when being tuned, and the rectangle facular of the output laser has been compressed to quasi-square through a prism. The size of the light source is 110 mm×80 mm×35 mm, and the output width is 0.07 nm, and tuning range is 4.6 nm. From experiment it can operate for 4 hours without any change of output light..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 181 (2005)
Study on directional prism resonator to improve the laser beam quality of repetition rate DPL
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The factors that deteriorate beam quality of repetition DPL include maladjustment of resonator, un-even distribution of pumped light and thermal effect of working medium. Directional prism is as entirely reflect mirror which builds up critical resonator with piano output mirror, and it realizes symmetry gain in side puThe factors that deteriorate beam quality of repetition DPL include maladjustment of resonator, un-even distribution of pumped light and thermal effect of working medium. Directional prism is as entirely reflect mirror which builds up critical resonator with piano output mirror, and it realizes symmetry gain in side pumped cavity, optical compensation to thermal effect and optical axis self-correction. Directional prism resonator works in Conductive cooling, side pumped DPL with frequency of 40 Hz, experiment results are as follows: 0.532 μm laser energy is of 53.2 mJ, stability of output energy is of 0.5%, pulse width is of 7.5 ns and the stability of frequency is of 0.025%, original beam divergence is of 2.8 mrad, laser axis is nearly nil-drift in two hours, and the beam distribution in far field is steady..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 186 (2005)
Analysis of the quantum neurodynamics
[in Chinese], [in Chinese], and [in Chinese]
Quantum neural computation is a new paradigm based on the combination of classical neural computation and quantum computation, and it has the value for theoretic study and the potential of application, The intrinsic relation between the two computational paradigms was discussed. The theoretical foundation of the quantuQuantum neural computation is a new paradigm based on the combination of classical neural computation and quantum computation, and it has the value for theoretic study and the potential of application, The intrinsic relation between the two computational paradigms was discussed. The theoretical foundation of the quantum neurodynamics were analyzed in detail. Finally some other related problems about quantum neural computation were discussed..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 192 (2005)
Quantum nonlocality and entanglement for a two-mode squeezed vacuum state in a phase damping channel
[in Chinese], and [in Chinese]
We study dynamics of quantum nonlocality and entanglement for a two-mode squeezed vacuum state in a phase damping channel. After getting the explicit expression of the density evolution operator of the system, we uncover the nonlocality of the state by introducing appropriate Bell operator based on the 'pseudospin We study dynamics of quantum nonlocality and entanglement for a two-mode squeezed vacuum state in a phase damping channel. After getting the explicit expression of the density evolution operator of the system, we uncover the nonlocality of the state by introducing appropriate Bell operator based on the 'pseudospin operator'. The property of the entanglement for the state is also clear from the calculation of relative entropy of entanglement..
Chinese Journal of Quantum Electronics
- Publication Date: Jan. 01, 1900
- Vol. 22, Issue 2, 196 (2005)
Level-splitting of the two-level entangled atoms moving in an optical field
[in Chinese], [in Chinese], and [in Chinese]
Using the semi-classical theory, the wave functions and the level-split of a two-atom entangled system moving in the optical field with circular polarization are described in the paper. Based on the analysis of the wave functions of the system, the level-split of moving entangled atoms can be shown.Using the semi-classical theory, the wave functions and the level-split of a two-atom entangled system moving in the optical field with circular polarization are described in the paper. Based on the analysis of the wave functions of the system, the level-split of moving entangled atoms can be shown..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 200 (2005)
Evolution properties of the field entropy in the system of the SU(1,1) coherent states field interacting with a four-level atom
[in Chinese], and [in Chinese]
Using the method of the systematic state vector the field entropy of the two-mode SU(1,1) coherent states field interacting with four-level atom has been formulated.The influences of the initial field strength and the atom-field coupling constant on the field entropy have been investigated. The results obtained by meanUsing the method of the systematic state vector the field entropy of the two-mode SU(1,1) coherent states field interacting with four-level atom has been formulated.The influences of the initial field strength and the atom-field coupling constant on the field entropy have been investigated. The results obtained by means of numerical show that. With the increase of the initial field parameter q and ζ, the mean values of the evolution curves of the field entropy increase constantly and so do the oscillation frequency of the evolution curves of the field entropy. The larger the value of ζ is. the more obvious the periodicity of the evolution curves of the initial field entropy are, but the obviously smaller the oscillation amplitude values become. With the increase of the coupling constant, the mean values of the evolution curves of the field entropy do not obviously change, but the oscillation frequency increase largely, the oscillation amplitude decrease a little and get to stability after some time, This show that the field entropy is susceptible to the atom-field coupling constant..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 206 (2005)
Entropy evolution properties of the field in the system of the cascade three-level atom interacting with binomial state for radiation field
[in Chinese], [in Chinese], and [in Chinese]
The entropy evolution properties of the field in the system of the cascade three-level atom interacting with binomial state for radiation field is studied. The results indicate that the field entropy is influenced by the field parameters η and M. With the increasing of the value of η or M. the maximum value and averageThe entropy evolution properties of the field in the system of the cascade three-level atom interacting with binomial state for radiation field is studied. The results indicate that the field entropy is influenced by the field parameters η and M. With the increasing of the value of η or M. the maximum value and average value of the field entropy is increasing. and the related degree of the field-atom is getting stronger and stronger. When the value of η M is large, the evolution curves of the field entropy display the phenomenon of collapse and revival, with the increasing of time, the revival oscillation frequency of the evolution curves of the field entropy becomes large obviously..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 217 (2005)
Interaction of a Ξ-type three-level moving atom and a single-mode field in an additional Kerr medium
[in Chinese], [in Chinese], and [in Chinese]
Antibunching effect is investigated in the system of a Ξ-type three-level moving atom interacting with a single-mode field in Kerr medium, and how the second-order correlation function is influenced by Kerr medium and atomic motion.Antibunching effect is investigated in the system of a Ξ-type three-level moving atom interacting with a single-mode field in Kerr medium, and how the second-order correlation function is influenced by Kerr medium and atomic motion..
Chinese Journal of Quantum Electronics
- Publication Date: Jan. 01, 1900
- Vol. 22, Issue 2, 223 (2005)
Squeezing effects of the mesoscopic LC circuit
[in Chinese], [in Chinese], and [in Chinese]
According to the fact that a mesoscopic capacitor can be regarded as a mesoscopic junction, we restudied the quantum effects of the mesoscopic LC circuit. The study shows: considering the coupling effects of the mesoscopic capacitor, the mesoscopic LC circuit will evolve from the vacuum state to a squeezing vacuum statAccording to the fact that a mesoscopic capacitor can be regarded as a mesoscopic junction, we restudied the quantum effects of the mesoscopic LC circuit. The study shows: considering the coupling effects of the mesoscopic capacitor, the mesoscopic LC circuit will evolve from the vacuum state to a squeezing vacuum state. We also research the quantum fluctations of the squeezing vacuum state..
Chinese Journal of Quantum Electronics
- Publication Date: Jan. 01, 1900
- Vol. 22, Issue 2, 227 (2005)
Effect of temperature on the nonlinear optical properties of metal/cermet films with shape distribution
[in Chinese]
The temperature dependence of the effective nonlinear optical properties is investigated in the random metal/cermet films with a shape distribution of metal particles. We adopt the normal Maxwell-Garnett model and obtain an analytical expression for the spectral density function of two-component composites in which theThe temperature dependence of the effective nonlinear optical properties is investigated in the random metal/cermet films with a shape distribution of metal particles. We adopt the normal Maxwell-Garnett model and obtain an analytical expression for the spectral density function of two-component composites in which the metallic inclusions possess a shape distribution P(L) of geometric. Numerical results show that the optical nonlinearity enhancement dependence on the temperature and volume fraction of component, and accompanied by a slight blueshift of the resonant peak..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 232 (2005)
Study on Zn composition distributions in Cd1-xZnxTe wafers grown in the Shenzhou 3 by micro-photoluminescence
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
We report the study on Zn composition distributions in Cd0.96Zn0.04Te wafers grown in Shenzhou 3 spacecraft by micro-photoluminescence (μ-PL). The PL is performed over the crystalized " crust " region and the plateau regions in the " core " which are surrounded by non-crystalized solvent and resulteWe report the study on Zn composition distributions in Cd0.96Zn0.04Te wafers grown in Shenzhou 3 spacecraft by micro-photoluminescence (μ-PL). The PL is performed over the crystalized " crust " region and the plateau regions in the " core " which are surrounded by non-crystalized solvent and resulted from incomplete melting of the raw material during the growth. Each PL spectrum has been fitted theoretically, resulting in the energy band gap Eg. The distributions of Eg are correlated to the Zn composition distributions. The results give out the variation trend and the statistical characteristics of the Zn composition distributions. An earth-grown CdZnTe wafer has been measured for comparison..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 238 (2005)
Interface optical phonon modes and their interactions with electron in coupling quantum systems
[in Chinese]
By using the transfer matrix method, within a framework of the dielectric continuum (DC) approximation, uniform descriptions for the interface optical (IO) phonon modes as well as the corresponding electron-IO phonon interaction Hamiltonians in n-layer coupling reduced-dimensionality systems (including the coupling quaBy using the transfer matrix method, within a framework of the dielectric continuum (DC) approximation, uniform descriptions for the interface optical (IO) phonon modes as well as the corresponding electron-IO phonon interaction Hamiltonians in n-layer coupling reduced-dimensionality systems (including the coupling quantum well (CQW), coupling quantum-well wire (CQWW) and coupling quantum dot (CQD) have been presented. Numerical calculations on a three-layer AlGaAs/GaAs systems placed in vacuum are performed, and the dependences of the IO phonon frequencies on the wave-vector or the quantum number in these systems are presented. Especial for the case of that the wave-vector or the quantum number approach 0 and infinity, reasonable explanations from the viewpoints of mathmetics and physics are given, respectively..
Chinese Journal of Quantum Electronics
- Publication Date: Jan. 01, 1900
- Vol. 22, Issue 2, 243 (2005)
Study on Schottky barrier of 4H-SiC at different anealing temperature
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Schottky barriers were formed by sputtering the metals on the front side of 4H-SiC(Si face) by magnetron sputtering to study the rectifying characteristics of the contacts between the metals and 4H-SiC. The infections of the annealing under different temperature were also studied. Schottky barrier height (SBH) of metalSchottky barriers were formed by sputtering the metals on the front side of 4H-SiC(Si face) by magnetron sputtering to study the rectifying characteristics of the contacts between the metals and 4H-SiC. The infections of the annealing under different temperature were also studied. Schottky barrier height (SBH) of metal/4H-SiC was evaluated from I-V measurements. Under a reverse voltage about 100 V, the reverse leaky current is below 0.1 nA. After annealed, the SBH of Cu/, Ni/4H-SiC was increased, but the SBH of Cr/, Ag/4H-SiC contact was decreased. The relationship between the work function of metals and the SBH was presented. The barrier height depends on the metal work function with slopes of 0.1 to 0.2 (except metal Cr)..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 251 (2005)
Theoretical model of all optical wavelength conversion based on ED-NALM
[in Chinese], and [in Chinese]
The theoretical model of all optical wavelength conversion based on an erbium-doped nonlinear amplifying fiber loop mirror is proposed. We focus on the peak power, pulse width, extinction ratio of conversion optical pulse and the transmission property of conversion optical pulse in standard single mode fiber. The resulThe theoretical model of all optical wavelength conversion based on an erbium-doped nonlinear amplifying fiber loop mirror is proposed. We focus on the peak power, pulse width, extinction ratio of conversion optical pulse and the transmission property of conversion optical pulse in standard single mode fiber. The results show that the conversion optical pulse has higher peak power and extinction ratio and shorter pulse width by using the model, and positive chirp is linear in the middle part of the conversion pulse. When the conversion optical pulse is transmitting in standard single mode fiber, the peak power will first increase then decrease, and the variation of pulse width is opposite as peak power..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 256 (2005)
Theoretical studies on the doped concentration of broadband erbium-doped tellurite-based optical fiber amplifier
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The characterization of the multi-channel gain spectrum for erbium-doped tellurite-based fiber amplifier(EDTFA) in WDM system is presented theoretically. The numerical simulation results show that the effect of erbium-doped concentration on each channel signal gain is different when the pumping configuration, pumping pThe characterization of the multi-channel gain spectrum for erbium-doped tellurite-based fiber amplifier(EDTFA) in WDM system is presented theoretically. The numerical simulation results show that the effect of erbium-doped concentration on each channel signal gain is different when the pumping configuration, pumping power and fiber length are given. With the increasing erbium-doped concentration in tellurite-bascd fiber, the signal gain of shorter wavelength channels easily tends to saturate and attenuates quickly compared to that of the longer wavelength channels, also the multi-channel signal gain spectrum shrinks to L band..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 261 (2005)
Vector modulation instability in high birefringence fibers
[in Chinese], and [in Chinese]
The coherently coupled nonlinear Schrodinger (NLS) equation of the propagation of a light pulse in a fiber has been utilized. We have studied modulation instability of linearly polarized light not only in anomalous dispersion regime but also in normal dispersion regime when the intensities along the two birefringence aThe coherently coupled nonlinear Schrodinger (NLS) equation of the propagation of a light pulse in a fiber has been utilized. We have studied modulation instability of linearly polarized light not only in anomalous dispersion regime but also in normal dispersion regime when the intensities along the two birefringence axes are equal. The results show that the input pulses have different gain spectra obviously when input power regime is different, both in anomalous dispersion regime and in normal dispersion regime. Furthermore, the gain spectra is different for different intrinsic birefringence when power of input pulse is invariable..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 267 (2005)
Compensation and influence of second order PMD on high bit rate optical fiber system
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The influences of second order PMD on light pulse are discussed. The results by number simulation show that the second-order polarization mode dispersion (PMD) components associated with depolarization of the principal states can cause significant system impairments. By the same time the compensation method for second-The influences of second order PMD on light pulse are discussed. The results by number simulation show that the second-order polarization mode dispersion (PMD) components associated with depolarization of the principal states can cause significant system impairments. By the same time the compensation method for second-order PMD are also discussed by theoretically and experimentally. The experiment results show that it is very effective to compensate second order PMD by using two stage PMD compensator..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 272 (2005)
Analysis on stress and modal field of bow-tie and elliptical cladding polarization-maintaining optical fiber
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Using finite element method, thermal stress characteristics and birefringence of stress-induced and modal fields of polarization-maintaining optical fiber (PMF) with bow-tie shape and elliptical cladding shape are analyzed. Stress and birefringence distribution of PMF are gave. Variation laws of fiber-core birefringencUsing finite element method, thermal stress characteristics and birefringence of stress-induced and modal fields of polarization-maintaining optical fiber (PMF) with bow-tie shape and elliptical cladding shape are analyzed. Stress and birefringence distribution of PMF are gave. Variation laws of fiber-core birefringence and mode birefringence with inner radii of stress regions to bow-tie shape PMF are demonstrated, and variation laws of fiber-core birefringence and mode birefringence with change of elliptical ratio of elliptical cladding PMF arc demonstrated. The effects of the stress domain structure of the fiber on stress birefringence and modal birefringence are investigated and compared ..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 277 (2005)
Numerical simulation of the all-fiber compact compressor based on cascaded uniform fiber gratings
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The evolution of picosecond pulses in cascaded fiber gratings has been simulated and analyzed. The numerical results show that picosecond pulses can be compressed effectively, if the parameters of gratings and pulses were chosen properly. The further study reveals that output pulses could become narrower and the fiber The evolution of picosecond pulses in cascaded fiber gratings has been simulated and analyzed. The numerical results show that picosecond pulses can be compressed effectively, if the parameters of gratings and pulses were chosen properly. The further study reveals that output pulses could become narrower and the fiber gratings needed would be shorter, if the negative chirp were induced by pulse laser..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 282 (2005)
Simulation of light source's spectrum signal of fiber-optic Fabry-Perot interferometer based on MATLAB
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
According to the relationship between fiber-optical F-P cavity longitudinal change of a low reflectivity and intensity of the interferometric light, we calculated the spectrum signal of light source with MATLAB. Using this method, we have obtained the spectrum signal of He-Ne laser whose wavelength is 632.8nm. The resuAccording to the relationship between fiber-optical F-P cavity longitudinal change of a low reflectivity and intensity of the interferometric light, we calculated the spectrum signal of light source with MATLAB. Using this method, we have obtained the spectrum signal of He-Ne laser whose wavelength is 632.8nm. The result shows that this method has the advantages of simple, convenient and high precision, and also can present helpful reference to experiment..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 286 (2005)
Analyses and measurement of stretch strain based on fiber Bragg grating
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Using the sensitive characteristic of fiber grating, the standard thread steel bar has been measured in our experiments. The data measured by FBG and resistance strain chip are compared with their theoretical values. The measured strain sensitivity of FBG2 is 15.647 με/kN approaching to the theoretical value 15.680 με/Using the sensitive characteristic of fiber grating, the standard thread steel bar has been measured in our experiments. The data measured by FBG and resistance strain chip are compared with their theoretical values. The measured strain sensitivity of FBG2 is 15.647 με/kN approaching to the theoretical value 15.680 με/kN, and the strain sensitivity of resistance strain chip is only 14.162 με/kN. Moreover, an applied method to measure the elasticity modulus of material by FBG is proposed. Measured value of FBG2 is 2.03× 105MPa equal to the standard value of elasticity modulus of material. The results indicate that the measurement of fiber grating is more effective and exact compared with the resistance strain chip as a strain measurement instrument..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 290 (2005)
Visible outfield calibration for FY-2 multi-channel scan radiometer
[in Chinese], [in Chinese], and [in Chinese]
Visible calibration is one of the key technologies for multi-channel scan radiometer (MCSR) on FY-2 geostationary meteorological satellite. Accurate pre-launch calibration is the base and foundation for applications of meteorological information. According to the Beer principle, a set of technique and process fit for FVisible calibration is one of the key technologies for multi-channel scan radiometer (MCSR) on FY-2 geostationary meteorological satellite. Accurate pre-launch calibration is the base and foundation for applications of meteorological information. According to the Beer principle, a set of technique and process fit for FY-2 MCSR are provided and set up to accomplish the outfield visible calibration in Kunming. We also analyze the error and tolerance sources to substantiate and improve our experiment data, which validates that all results are credible and satisfied..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 295 (2005)
Lidar geometrical form factor and its effect on aerosol detection
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Lidar geometrical form factor of coaxial and biaxial transmitter-receiver systems are described. Theoretical method and experimental ones for calculating geometrical form factor are presented. Some examples of geometrical form factor correction are introduced and the misalignment effects on aerosol extinction are analyLidar geometrical form factor of coaxial and biaxial transmitter-receiver systems are described. Theoretical method and experimental ones for calculating geometrical form factor are presented. Some examples of geometrical form factor correction are introduced and the misalignment effects on aerosol extinction are analyzed based on many experiments of AML-1 lidar. It is concluded that the geometrical form factor is very sensitive to misalignment in the optical system, which would arise much more errors for the aerosol extinction. But the geometrical form factor will be stability when the lidar system is reliable and optical system is correct..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 299 (2005)
Influence of the motion of atomic mass centre and field mode structure on the field entropy squeezing
[in Chinese], and [in Chinese]
The influence of the motion of atomic mass centre, field mode structure and initial mean photon number on the field entropy squeezing is investigated by means of the theory of quantum information entropy. It is shown that the motion of atomic mass center leads to the periodic evolution of the field entropy squeezing anThe influence of the motion of atomic mass centre, field mode structure and initial mean photon number on the field entropy squeezing is investigated by means of the theory of quantum information entropy. It is shown that the motion of atomic mass center leads to the periodic evolution of the field entropy squeezing and this period depends on the field mode structure parameter;an increase in field-mode structure parameter results in not only shortening of the evolution period of the field entropy squeezing but also prolonging of the squeezing time;the field may exhibit long time entropy squeezing effect for some choieed system parameters..
Chinese Journal of Quantum Electronics
- Publication Date: Apr. 01, 2005
- Vol. 22, Issue 2, 1297 (2005)
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