Journals >Chinese Journal of Quantum Electronics
Contents
2007
Volume: 24 Issue 4
25 Article(s)
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Research Article
Survey of microchip lasers
Shu-xiang WANG, Yun-lin CHEN, Cai-fan YAN, He ZHAN, Jing-jun XU, and Guang-yin ZHANG
Microchip lasers have compactly simplified construction,longer coherent length,higher lightness,single-frequency and single-longitudinal-mode output,so they become one of focuses in the field of solid state lasers. A summary on technical characteristics and applications of microchip lasers are presented. Especially,recMicrochip lasers have compactly simplified construction,longer coherent length,higher lightness,single-frequency and single-longitudinal-mode output,so they become one of focuses in the field of solid state lasers. A summary on technical characteristics and applications of microchip lasers are presented. Especially,recent achievements and applications on microchip lasers are described,the restricted factors of the microchip laser developments are analyzed and the future of microchip lasers is discussed..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 401 (2007)
Study and development of coherent addition techniques of laser beam
Bing LEI, Ying FENG, Li-an WEI, and Ze-jin LIU
The study of coherent addition techniques of fiber laser is very significant to obtain the laser with high power and good beam quality simultaneously,and the coherent addition techniques of other lasers have vital suggestive action on them. The basic principle and development of coherent addition techniques of laser beThe study of coherent addition techniques of fiber laser is very significant to obtain the laser with high power and good beam quality simultaneously,and the coherent addition techniques of other lasers have vital suggestive action on them. The basic principle and development of coherent addition techniques of laser beam are introduced. The various coherent addition methods are classified according to their combining mechanism,and the mechanism and difficulty of these methods are expounded in details. Finally,the comparisons and simple comments about the methods are discussed,and the three promising coherent addition methods are indicated..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 407 (2007)
Beam shaping of excimer laser used for lithography and its research progress
Qing-hua LIN, Chao SONG, Lu-bin WANG, and Jin-yun ZHOU
The causes for beam-shaping of excimer laser in the application of lithography and the results of the beam spatial intensity profiles before and after shaping are expounded. The method of theoretical modeling-Gaussian-Schell model built-up for beam-shaping of excimer is also introduced. The advantages and defects,incluThe causes for beam-shaping of excimer laser in the application of lithography and the results of the beam spatial intensity profiles before and after shaping are expounded. The method of theoretical modeling-Gaussian-Schell model built-up for beam-shaping of excimer is also introduced. The advantages and defects,including the shaping capability,the energy loss,the interference effect,the control of wavefront and uniform distribution of amplitude,etc.,of beam-homogenizer such as microlens array and diffractive phase grating and so on used for lithographic beam-shaping are summarized and analyzed. Moreover,the principles,characteristics and progress of the beamshaper are brief reviewed..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 415 (2007)
Boundary reflection from the sunk curved liquid surface and its applications
Feng ZHU, Run-cai MIAO, and Dao-bin LUO
The distensible effect of a strip-shape bright region light reflection from curved liquid surface was discovered. When a collimated laser beam illumines the sunk curved liquid surface by two parallel wetting plate,the special reflective patterns,which correspond to the boundary light reflection,can be produced. In factThe distensible effect of a strip-shape bright region light reflection from curved liquid surface was discovered. When a collimated laser beam illumines the sunk curved liquid surface by two parallel wetting plate,the special reflective patterns,which correspond to the boundary light reflection,can be produced. In fact,there is the pattern with a strip-shape bright region in the center,the high visibility diffraction fringes,dark region both sides and the width of bright region become big with the increased width of the incident beam. The relation of the width of the bright region and the width of the incident beam was derived theoretically. Subsequently,the slope,the contact angle and the surface height of liquid surface were calculated. It is believed that the distensible effect of a strip-shape bright region is capable of real time characterization of curved liquid surface..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 420 (2007)
Application of a BP neural network based on genetic algorithm in image compression
Shi-fang WANG, and Guo-li LI
Artificial neural networks(ANN)and genetic algorithm(GA)are both theories for intelligent information processing,but there are limitations in these algorithms. Combining genetic algorithm with BP neural networks,an improved algorithm for image compression using a mixed BP neural network(BP-GA)is proposed. It looks on tArtificial neural networks(ANN)and genetic algorithm(GA)are both theories for intelligent information processing,but there are limitations in these algorithms. Combining genetic algorithm with BP neural networks,an improved algorithm for image compression using a mixed BP neural network(BP-GA)is proposed. It looks on the network weights as a unitary chromosome that is operated by the three genetic operators including selection,crossover and mutation as the normal genetic algorithm. The experimental results show that the mixed algorithm can avoid premature saturation and have higher compression rate and better effect in image compression..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 425 (2007)
Study on image restoration method based on prior information and regularization technique
Sheng-hua XIE, Qi-heng ZHANG, and Ding SU
A blind deconvolution image restoration algorithm based on prior information and regularization technique is proposed to eliminate the influence of atmospheric turbulence in the turbulence-degraded image restoration method. The basic principle of the algorithm is maximum likelihood theory. It uses the information of obA blind deconvolution image restoration algorithm based on prior information and regularization technique is proposed to eliminate the influence of atmospheric turbulence in the turbulence-degraded image restoration method. The basic principle of the algorithm is maximum likelihood theory. It uses the information of object image and point spread function(PSF),and transforms them into the penalizing function of maximum likelihood. At the same time,the regularization technique is introduced in the course of estimating object image and PSF to enhance the convergence speed and stability of the algorithm. The result of image restoration experiment shows when the model of turbulence-degrade is entirely unknown the algorithm can effectively realize the reconstruction of degraded image..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 429 (2007)
Eigen-polarization of corner-cube cavity
Gong-min YAO, Li-xin XU, Wei-qing GAO, Hai MING, Yong CHENG, Xiao-bing WANG, and Bin SUN
The polarization properties of the corner-cube cavity are analyzed by use of the Jones matrix. The eigen-polarization of corner-cube cavity is discussed for the first time.These eigen-polarizations are two independent polarizations,and they are linear polarizations when the operation material in the corner-cube cavity The polarization properties of the corner-cube cavity are analyzed by use of the Jones matrix. The eigen-polarization of corner-cube cavity is discussed for the first time.These eigen-polarizations are two independent polarizations,and they are linear polarizations when the operation material in the corner-cube cavity is isotropic. This result explains the coherent properties of the output light of the corner-cube cavity theoretically..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 434 (2007)
Analysis of the peak profile in time-of-flight mass spectrum
Shu-dong ZHANG, Ming-xia ZHANG, Yan WANG, Xiang-jun ZHU, and Xiang-he KONG
A new phenomenon is observed when we use YAG 355 nm laser to ionize water/methanol mixture molecular beam and detect the ions with time-of-flight mass spectrometer. The peaks position of mass ions shift when changing the laser delay time to the molecular beam or singly changing laser energy while keeping other conditioA new phenomenon is observed when we use YAG 355 nm laser to ionize water/methanol mixture molecular beam and detect the ions with time-of-flight mass spectrometer. The peaks position of mass ions shift when changing the laser delay time to the molecular beam or singly changing laser energy while keeping other conditions not changed. It can be determined by analyzing mass spectra that the peak's shift does not mean new ions appear.The reason is deduced to the voltage fluctuation on the extract electrode of TOF when ions passing through the grating electrode and parts of them are being absorbed. The ion's shift altitude is proportion with the ion's intensity,and the ion's total flight time is shortened with ion's intensity increasing. The numerical simulation of charged-particle's movement in electrical field also supports the deduction and is consistent with the experimental results..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 438 (2007)
Multiphoton ionization and dissociation of CH3I at 355 nm
Li LI, Xiang-he KONG, Shu-dong ZHANG, Cun-hai LIU, Zhi-qing SUN, Jian-ping LIU, Liang-fang ZHANG, and Guang QIAO
The mechanisms of multiphoton ionization(MPI)and dissociation of CH3I at 355 nm are studied under supersonic beam conditions with time-of-flight mass spectrometer. MPI mass spectrum consists mostly of fragment ions,H+,CH(+,3)and I+. In addition,weak signals of C+,CH+,CH(+,2),and CH3I+ are also observed in the spectrum.The mechanisms of multiphoton ionization(MPI)and dissociation of CH3I at 355 nm are studied under supersonic beam conditions with time-of-flight mass spectrometer. MPI mass spectrum consists mostly of fragment ions,H+,CH(+,3)and I+. In addition,weak signals of C+,CH+,CH(+,2),and CH3I+ are also observed in the spectrum. This is consistent with the parent-ion ladder mechanism in which the parent molecules are two-photon resonantly excited to Rydberg C state and then ionized through an additional one-photon absorption to form CH3I+. Fragment ions are produced by dissociating CH3I. According to the appearance potential of the parent and fragment ions,the main possible channels of the MPI and photo dissociation of CH3I are analyzed..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 443 (2007)
Rb(5PJ)+(Ne,N2)collisional energy transfer
Jin XU, Qing WANG, Ghupur Yasenjin, Kang DAI, and Yi-fan SHEN
The collisional energy transfer in Rb(5PJ)+M collisions,where M=Ne,N2 under gas cell conditions was investigated. For collision with Ne only electronic to translational energy transfer is possible. However,in the N2 case,electronics to vibrational or rotational transfer is important. The Rb(5P3/2)state is excited by a The collisional energy transfer in Rb(5PJ)+M collisions,where M=Ne,N2 under gas cell conditions was investigated. For collision with Ne only electronic to translational energy transfer is possible. However,in the N2 case,electronics to vibrational or rotational transfer is important. The Rb(5P3/2)state is excited by a tunable CW diode laser,where the laser is tuned slightly off resonance. The ratio of 5P1/2→5S1/2to the 5P3/2→5S1/2 fluorescence as a function of quenching gas pressure was measured. Using a two-state rate equation model the transfer rate coefficients from the Rb(5PJ)state was obtained. The rate coefficient for 5P3/2→5P1/2 transfer in collision with Ne is 1.53×10－12cm3S－1. Using the ratio of the 5P1/2 to 5P3/2 fluorescence for Ne and N2 case,and fitting the experimental results to the rate equation analysis,we estimate that the rate coefficient for 5P3/2→5P1/2 transfer in collision with N2 is 8.83×10－11 cm3s－1. The quenching rate coefficient of the 5PJ state is 1.25×10－10 cm3s－1. A qualitative explanation for the results was given..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 447 (2007)
Resonant energy transfer between quantum dots under near-field excitation
Guang-hui YUAN, Pei WANG, and Hai MING
We develop a theoretical framework for invesfigation of resonant energy transfer in complex environments under optical near-fields excitation. By combining the fieldsusceptibility formalism with the optical Bloch equations method,we derive the density matrix elements and their emitting signal intensity for the computatWe develop a theoretical framework for invesfigation of resonant energy transfer in complex environments under optical near-fields excitation. By combining the fieldsusceptibility formalism with the optical Bloch equations method,we derive the density matrix elements and their emitting signal intensity for the computation of the energy transfer between two quantum dots excited by optical near fields and placed in a complex geometry.It provides a theoretical method to investigate the resonant energy transfer between quantum dots at the microscale. Moreover,we consider the quantum dots luminescence intensity for different polarization incident light,the results show that the luminescence intensity can be strongly enhanced when the illumination polarization state is along the direction of the two quantum dots..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 451 (2007)
Coherence properties of radiation and absorption in the three-level atom
Feng GAO, Deng-yu ZHANG, and Mei-juan TANG
The interaction of the qubit with its environment induces the qubit dissipation or dephasing,which causes the qubit collapse from a coherent superposition state to a mixed or pure state. This process is known as quantum decoherence. The radiation and absorption of the three-level atom is studied. Basis on theories of qThe interaction of the qubit with its environment induces the qubit dissipation or dephasing,which causes the qubit collapse from a coherent superposition state to a mixed or pure state. This process is known as quantum decoherence. The radiation and absorption of the three-level atom is studied. Basis on theories of quantum mechanics and Kraus operator and utilizing the reducible density rectangular method the transformation of density matrix of the three-level atom which simultaneously in the case of the radiation and absorption is investigated. The coherence properties of quantum states are also investigated. If the early state of the three-level atom is coherence state,it may evolve to the coherent state,the partial mixed state completely,the completely state,and the pure state..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 456 (2007)
A quantum self-organization feature mapping networks and clustering algorithm
Pan-chi LI, and Shi-yong LI
A quantum self-organization feature mapping networks model and its clustering algorithm are presented. Both the input and the weight of the model are represented by the quantum bits,and the output of the model is represented by the real number. The model is composed of input layer and competitive layer. Firstly,the samA quantum self-organization feature mapping networks model and its clustering algorithm are presented. Both the input and the weight of the model are represented by the quantum bits,and the output of the model is represented by the real number. The model is composed of input layer and competitive layer. Firstly,the samples are transformed into quantum states and transported to the input layer,and then the similar coefficients of quantum states are computed between the input and the weight. Secondly,the competitive layer extracts the implicit pattern characters of the clustering samples and takes self-organization to them,and then output the clustering result. The quantum states of weight are modified by quantum rotation gates. The networks are trained by the algorithm of the unsupervised learning and supervised learning together. Finally two simulation experiments demonstrate that the model and algorithm are evidently superior to the general self-organization feature mapping networks..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 463 (2007)
Influence of the noise on geometric quantum gates
Ming ZHOU, and Lian HU
The ability of geometric quantum gate against the fluctuations of control external field was researched. We replace the random fluctuations by the periodic perturbation. In this approximation,the result shows that no matter the Berry geometry phase or the AharonovAnandan(A-A)geometry phase has the same ability against The ability of geometric quantum gate against the fluctuations of control external field was researched. We replace the random fluctuations by the periodic perturbation. In this approximation,the result shows that no matter the Berry geometry phase or the AharonovAnandan(A-A)geometry phase has the same ability against the stochastic fluctuations as their corresponding dynamics phases. And numerical results also justify that the Berry phase is more powerful to resist the external field fluctuation than that of the A-A phase. We believe that this distinction is caused by adiabatic approximation purely. Lastly,it is validated that the geometry quantum gates constructed by an orthogonal state scheme are more powerful against the fluctuations..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 469 (2007)
Teleportation of an unknown atomic state in cavity QED
Mei-feng CHEN, and Song-she MA
A scheme is proposed for teleportation of an unknown atomic state based on the nonresonant interaction of two coupled two-level atoms with a single-mode cavity field. The scheme only requires the cavity field to be in a coherent state. After the interaction between the atoms and the cavity,the cavity is left in a coherA scheme is proposed for teleportation of an unknown atomic state based on the nonresonant interaction of two coupled two-level atoms with a single-mode cavity field. The scheme only requires the cavity field to be in a coherent state. After the interaction between the atoms and the cavity,the cavity is left in a coherent state. By detecting the states of atoms,an unknown atomic state is teleported. The scheme can also be used to teleport an unknown atomic entangled state..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 475 (2007)
Entanglement dynamics of two entangled two-level atoms in the vacuum field
Hong-mei ZOU, and Mao-fa FANG
The entanglement dynamics of two partially entangled two-level atoms interacting with a single mode vacuum field is investigated. The entanglement dynamics between two partially entangled two-level atoms and the vacuum field is explored by using the quantum reduced entropy,and that between two two-level atoms is studieThe entanglement dynamics of two partially entangled two-level atoms interacting with a single mode vacuum field is investigated. The entanglement dynamics between two partially entangled two-level atoms and the vacuum field is explored by using the quantum reduced entropy,and that between two two-level atoms is studied by using the quantum relative entropy. The influences of the atomic dipole-dipole interaction intensity on the entanglement dynamics of the system are also discussed. The results show that the system exhibits periodic entanglement dynamics,and the magnitude and the period of entanglement depend on the atomic dipole-dipole interaction. The atom-field maximal entanglement state and atom-atom maximal entanglement state can be preparated by selecting appropriate system parameters and the interaction time..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 480 (2007)
Quantization and quantum effects of mesoscopic inductance coupling circuits with mutual inductance
Bao-long LIANG, Ji-suo WANG, and Xiang-guo MENG
The Hamiltonian of the mesoscopic inductance coupling circuits with mutual inductance was given by Langrangian function,then it was diagonilized through a unitary operator.The normal ordering form of the unitary operator was obtained by the technique of integration within an ordered product(IWOP),and the quantum fluctuThe Hamiltonian of the mesoscopic inductance coupling circuits with mutual inductance was given by Langrangian function,then it was diagonilized through a unitary operator.The normal ordering form of the unitary operator was obtained by the technique of integration within an ordered product(IWOP),and the quantum fluctuations of charge and its conjugate quantity of this system were discussed. It was found that a rotated two single-mode squeezed vacuum state could be generated by using the system..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 485 (2007)
Solitons of spinor Bose-Einstein condensates in an optical lattice
Yuan-dong XIE
An improved nonlinear equation different from usual and an improved soliton solution of spinor Bose-Einstein condensates(BES)in an optical lattice are obtained by taking into account a nonlinear term in the equation of motion for probability amplitude of spins carefully. The width,peak and energy of soliton are also foAn improved nonlinear equation different from usual and an improved soliton solution of spinor Bose-Einstein condensates(BES)in an optical lattice are obtained by taking into account a nonlinear term in the equation of motion for probability amplitude of spins carefully. The width,peak and energy of soliton are also found..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 491 (2007)
Signal demodulation algorithm of fiber optic gyroscope based on 3×3 coupler
Ying LI, and Xing-lin CHEN
Nonreciprocal structure open-loop fiber optic gyroscope(FOG)composed of 3×3 coupler has the advantages of high-sensitivity and wide-gauging range. The signal detection plays important role in the FOG system. The demodulation precision influences the maximum resolution of the gyro directly. According to characterisNonreciprocal structure open-loop fiber optic gyroscope(FOG)composed of 3×3 coupler has the advantages of high-sensitivity and wide-gauging range. The signal detection plays important role in the FOG system. The demodulation precision influences the maximum resolution of the gyro directly. According to characteristics of output signal model of FOG which uses 3×3 coupler,new signal demodulation algorithm is adopted. It can accurately demodulation arbitrary input of dynamic range. It overcomes disadvantage which is lowsensitivity round±π/2 work point,and improves precision of measured signal. Experimental results indicate that algorithm demodulate the measured physical variable quickly and exactly..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 495 (2007)
Study on improving the performance of the refractive index sensor based on long-period waveguide gratings
Zi-hao WANG, and Li YANG
A novel ambient refractive index sensor based on long period waveguide grating(LPWG)with a higher refractive index overlayer is proposed and investigated. The response of LPWG sensor to ambient refractive index change is simulated by studying the shift of resonance wavelength caused by the corresponding change of effecA novel ambient refractive index sensor based on long period waveguide grating(LPWG)with a higher refractive index overlayer is proposed and investigated. The response of LPWG sensor to ambient refractive index change is simulated by studying the shift of resonance wavelength caused by the corresponding change of effective refractive index of a certain higher-order mode. It is shown that the deposition of the overlayer will lead to the re-organization of high-order modes and then an abrupt change of the effective refractive index of the higher-order mode,which will greatly improve the sensitivity and operation range of LPWG refractive index sensor..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 500 (2007)
Switch characteristics of dispersion period lengths of dispersion-managed soliton
Fei LIU, Xue-ai YIN, and Lin YI
Models of periodic perturbations are constructed in a dispersion-managed soliton system,their influence on soliton propagation are investigated. By the method of fast Fourier transform(FFT),we numerically show that there are not only many extremums but also switch characteristics in dependence of the propagation distanModels of periodic perturbations are constructed in a dispersion-managed soliton system,their influence on soliton propagation are investigated. By the method of fast Fourier transform(FFT),we numerically show that there are not only many extremums but also switch characteristics in dependence of the propagation distance on the period lengths of perturbation,so we may control the propagation of soliton more benefically than ever..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 505 (2007)
Design of fiber optic rotary joint based on photonic crystal fiber
Feng XU, Wei JIANG, and Ben-li YU
Fiber optic rotary joint is used for signal transmission between stationary platform and rotary platform because of its advantages of high bandwidth,electromagnetic compatibility,small size,etc. A novel design of fiber optic rotary joint based on direct coupling technology of large mode area photonic crystal fiber(LMA-Fiber optic rotary joint is used for signal transmission between stationary platform and rotary platform because of its advantages of high bandwidth,electromagnetic compatibility,small size,etc. A novel design of fiber optic rotary joint based on direct coupling technology of large mode area photonic crystal fiber(LMA-PCF)is designed. The analysis results of coupling theory indicate that this design provides low insertion loss and decrease requirement of accuracy of machining and assembly. Because LMA-PCF possesses the properties of non-cut-off-wavelength single-mode and lower non-linear transmission,the PCF optic rotary joint could be effectively associated with technology of WDM to increase transmission capacity..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 510 (2007)
Influence of different incident medium on reflectance spectra of the GaN-based distributed Bragg reflector
Shu-wen ZHENG, Guang-han FAN, Shu-ti LI, and Tian-ming ZHOU
The reflected spectra of GaN-based DBR at different incident medium are studied theoretically by transfer matrix method. The results show that the reflectivity of DBR depends on the refractive index of the incident medium with quadratic function when the periods of GaN-AlxGa1－xN DBR are under 15 and the reflectivity isThe reflected spectra of GaN-based DBR at different incident medium are studied theoretically by transfer matrix method. The results show that the reflectivity of DBR depends on the refractive index of the incident medium with quadratic function when the periods of GaN-AlxGa1－xN DBR are under 15 and the reflectivity is about linear with the refractive index of the incident medium when the periods are over 15.Based on this relation,a simple formula is deduced in order to estimate the actual spectral reflectivity of DBR in LED. The differences of the reflected spectra of different GaN-based DBR at air and Al0.4Ga0.5In0.1N incident medium are analyzed in detail. A half-hybrid GaN-based DBR structure designed is more predominant than conventional DBR structure designed in reducing the difference of the reflectance spectra of DBR at different incident medium,improving material growth and enhancing light extraction of LED..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 514 (2007)
Influence of temperature on electrically tunable filter properties of ferroelectric liquid crystal
Xiang-zhong QIAN
The application and accuracy of improvement of electrical field tunable liquid crystal filter is difficult because the pitch and spontaneous polarization of ferroelectric liquid crystals are sensitive to temperature where the molecular direction is changed by electric field. Based on the changing relation of pitch and The application and accuracy of improvement of electrical field tunable liquid crystal filter is difficult because the pitch and spontaneous polarization of ferroelectric liquid crystals are sensitive to temperature where the molecular direction is changed by electric field. Based on the changing relation of pitch and spontaneous polarization of ferroelectric liquid crystal vs the temperature,the effect of temperature on birefringence of ferroelectric liquid crystal was discussed,the approximate formula of the transmission rate of ferroelectric liquid crystal electrically tunable filter properties according to the temperature was obtained. The effect of temperature on ferroelectric liquid crystal electrically tunable filter was numerically calculated.The results show that the transmission rate and band width increase and transmission peak wavelength moves to short wavelength as temperature increase,the effect of temperature changing on electrically tunable filter of ferroelectric liquid crystal is less than that of electrical field changing..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 519 (2007)
Photoluminescence of a mono-substituted polyacetylene at low temperatures
Fu-fang ZHOU, and Yuan-ming HUANG
The light emitting properties from solid films of a mono-substituted polyacetylene,poly{n-[(4＇-hexylcarbonyl-bipheny1-4-oxy)]-1-propyne},are investigated as temperature drops from 300 to 18 K. At room temperature,the solid films of the polymer give off intense green photoluminescence with its dominant emission band andThe light emitting properties from solid films of a mono-substituted polyacetylene,poly{n-[(4＇-hexylcarbonyl-bipheny1-4-oxy)]-1-propyne},are investigated as temperature drops from 300 to 18 K. At room temperature,the solid films of the polymer give off intense green photoluminescence with its dominant emission band and two minor emission bands located at 510,440 and 380 nm,respectively. The 510 and 440 nm emission bands can be assigned to the primary and the secondary excimer emissions of the polymer while the 380 nm emission band can be assigned to the emission from the isolated chain of the polymer. When the temperature drops from 300 to 18 K,the primary excimer emission band is red shifted from 510 to 560 nm while the secondary excimer emission at 440 nm disappears gradually,leaving the emission from isolated chain of the polymer separated from its excimer emission bands. These temperature-introduced changes in the photoluminescence are explained in terms of the morphological changes in the polymer at low temperature..
Chinese Journal of Quantum Electronics
- Publication Date: Oct. 11, 2021
- Vol. 24, Issue 4, 524 (2007)
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