This paper predicts that grey spatial solitons can exist in two-photon photorefractive materials. In steady state and undcr appropriate external bias conditions, it obtains the grey spatial soliton solutions of the op...This paper predicts that grey spatial solitons can exist in two-photon photorefractive materials. In steady state and undcr appropriate external bias conditions, it obtains the grey spatial soliton solutions of the optical wave evolution equation. The intensity profile, phase distribution, and transverse velocity of these grey solitons are discussed.展开更多
We have grown triply doped Mg:Fe:Mn:LiTaO3 crystals with near stoichiometry using the top seeded solution growth technique. The defect structure was investigated by infrared absorption spectra and Curie temperature. U...We have grown triply doped Mg:Fe:Mn:LiTaO3 crystals with near stoichiometry using the top seeded solution growth technique. The defect structure was investigated by infrared absorption spectra and Curie temperature. Using a blue laser as the source, excellent photorefractive properties were obtained. Nonvolatile holographic storage properties were investigated using the dual wavelength technique. We got a very high fixed diffraction efficiency and nonvolatile holographic storage sensitivity. The blue light has more than enough energy to excite holes of deep(Mn) and shallow(Fe) trap centers with the same phase, which enhance dramatically the blue photorefractive properties and the nonvolatile holographic storage. Mg2+ ion is no longer damage resistant at blue laser, but enhances photorefractive characteristics.展开更多
A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of...A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.展开更多
It has been suggested to use LiNbO3：Fe,Mn crystal for solving the problem of information volatility during the read-out process with all-optical facilities,but the minute order response time is far from the requireme...It has been suggested to use LiNbO3：Fe,Mn crystal for solving the problem of information volatility during the read-out process with all-optical facilities,but the minute order response time is far from the requirements for the real-time information processing.We present the nonvolatile holographic storage properties of LiNbO3：Hf,Fe,Mn.The response time is shortened to 5.0 s,and the sensitivity S is enhanced to 0.22 cm/J in this triply doped crystal.The experimental results show that the HfO2 doping threshold is 5.0 mol.%.Thus it seems that we have found a useful tetravalent dopant for LiNbO3：Fe,Mn that can obviously improve the nonvolatile holographic recording sensitivity.展开更多
The modulation instability of quasi-plane-wave optical beams is investigated in the frame of generalized SchrSdinger equation with the nonlinear term of a general form. General expressions are derived for the dispersi...The modulation instability of quasi-plane-wave optical beams is investigated in the frame of generalized SchrSdinger equation with the nonlinear term of a general form. General expressions are derived for the dispersion relation, the critical transverse spatial frequency, as well as the instability growth rate. The analysis generalizes the known results reported previously. A detailed discussion on the modulation instability in biased centrosymmetric photorefractive media is also given.展开更多
It is shown that bright-dark incoherently coupled soliton pairs can exist in photorefractive （PR） crystals under steady-state conditions, each soliton constituent of which is spatially incoherent. The characteristic...It is shown that bright-dark incoherently coupled soliton pairs can exist in photorefractive （PR） crystals under steady-state conditions, each soliton constituent of which is spatially incoherent. The characteristics of bright-dark incoherently coupled soliton pairs are studied by the coherent density approach and the intensity expressions of soliton pairs are obtained. The propagation properties of coherent components of each constituent in a soliton pair are also discussed in detail.展开更多
Cat mutually pumped phase conjugation configuration is discovered and investigated by using two-wave mixing in (KyNa1-y)2z(SrxBa1-x)1-zNb2O6 (KNSBN) crystal. When only one signal or pumped beam does not give birth to ...Cat mutually pumped phase conjugation configuration is discovered and investigated by using two-wave mixing in (KyNa1-y)2z(SrxBa1-x)1-zNb2O6 (KNSBN) crystal. When only one signal or pumped beam does not give birth to phase conjugation, the maximum reflectivity of signal and pumped beam attain 140% and 30% due to two-wave mixing, respectively. The experimental results show that the two-wave mixing can reduce the threshold of incident beams power, extend the incident angle range, and shorten response rate in the process of self-pumped phase conjugator (SPPC) in KNSBN crystal.展开更多
We show self-coupled and cross-coupled vector beam evolution equations in the low-amplitude regime for screening solitons, which can exhibit the analytical solutions of bright-bright and dark-dark vector solitons. Our...We show self-coupled and cross-coupled vector beam evolution equations in the low-amplitude regime for screening solitons, which can exhibit the analytical solutions of bright-bright and dark-dark vector solitons. Our analysis indicates that these self-coupled vector solitons are obtained irrespective of the intensities of the two optical beams, whereas these cross-coupled vector solitons can be established when the intensities of the two optical beams are equal. Relevant examples are provided where the photorefractive crystal is lithium niobate (LiNbO3). The stability properties of these vector solitons have been investigated numerically and it has been found that they are stable.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 60508005）, and Scientific Research Foundation of Harbin Institute of Technology of China （Grant No HIT. 2003. 31）.
文摘This paper predicts that grey spatial solitons can exist in two-photon photorefractive materials. In steady state and undcr appropriate external bias conditions, it obtains the grey spatial soliton solutions of the optical wave evolution equation. The intensity profile, phase distribution, and transverse velocity of these grey solitons are discussed.
基金Project supported by the National Natural Science Foundation of China （Grant No. 51202045）, the Postdoctoral Science Foundation of Heilongjiang Province, China, and the Fundamental Research Funds for the Central Universities of Ministry of Education of China （Grant No. HIT. NSRIF. 2013004）.
文摘We have grown triply doped Mg:Fe:Mn:LiTaO3 crystals with near stoichiometry using the top seeded solution growth technique. The defect structure was investigated by infrared absorption spectra and Curie temperature. Using a blue laser as the source, excellent photorefractive properties were obtained. Nonvolatile holographic storage properties were investigated using the dual wavelength technique. We got a very high fixed diffraction efficiency and nonvolatile holographic storage sensitivity. The blue light has more than enough energy to excite holes of deep(Mn) and shallow(Fe) trap centers with the same phase, which enhance dramatically the blue photorefractive properties and the nonvolatile holographic storage. Mg2+ ion is no longer damage resistant at blue laser, but enhances photorefractive characteristics.
文摘A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.
基金Project supported by the National Advanced Materials Committee of China (Grant No. 2007AA03Z459)Shanxi Provincial Technology Project for Higher Education,China (Grant No. 20091105)
文摘It has been suggested to use LiNbO3：Fe,Mn crystal for solving the problem of information volatility during the read-out process with all-optical facilities,but the minute order response time is far from the requirements for the real-time information processing.We present the nonvolatile holographic storage properties of LiNbO3：Hf,Fe,Mn.The response time is shortened to 5.0 s,and the sensitivity S is enhanced to 0.22 cm/J in this triply doped crystal.The experimental results show that the HfO2 doping threshold is 5.0 mol.%.Thus it seems that we have found a useful tetravalent dopant for LiNbO3：Fe,Mn that can obviously improve the nonvolatile holographic recording sensitivity.
基金This work was supported by the National Natural Sci- ence Foundation of China (No. 10374121) the Nat- ural Science Foundation of Guangdong Province, China (No. 031567).
文摘The modulation instability of quasi-plane-wave optical beams is investigated in the frame of generalized SchrSdinger equation with the nonlinear term of a general form. General expressions are derived for the dispersion relation, the critical transverse spatial frequency, as well as the instability growth rate. The analysis generalizes the known results reported previously. A detailed discussion on the modulation instability in biased centrosymmetric photorefractive media is also given.
基金This work was supported in part by Shanghai Leading Academic Disciplines (No. T0102 and T0104) China Postdoctoral Science Foundation (No. 2004036317) Shanghai Postdoctoral Science Foundation, Shanghai Key Laboratory of Special Fiber Optics (Shanghai University) .
文摘It is shown that bright-dark incoherently coupled soliton pairs can exist in photorefractive （PR） crystals under steady-state conditions, each soliton constituent of which is spatially incoherent. The characteristics of bright-dark incoherently coupled soliton pairs are studied by the coherent density approach and the intensity expressions of soliton pairs are obtained. The propagation properties of coherent components of each constituent in a soliton pair are also discussed in detail.
基金This work was supported by a grant from the Key Re-search Project No.2 in the Climbing Program from the State Science and Technology Commission of China, and partially supported by the Young National Science Foun-ation of shandong University.
文摘Cat mutually pumped phase conjugation configuration is discovered and investigated by using two-wave mixing in (KyNa1-y)2z(SrxBa1-x)1-zNb2O6 (KNSBN) crystal. When only one signal or pumped beam does not give birth to phase conjugation, the maximum reflectivity of signal and pumped beam attain 140% and 30% due to two-wave mixing, respectively. The experimental results show that the two-wave mixing can reduce the threshold of incident beams power, extend the incident angle range, and shorten response rate in the process of self-pumped phase conjugator (SPPC) in KNSBN crystal.
基金This work was supported by the National Natural Sci-ence Foundation of China (No. 60078004)by the Director Foundation of Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences.
文摘We show self-coupled and cross-coupled vector beam evolution equations in the low-amplitude regime for screening solitons, which can exhibit the analytical solutions of bright-bright and dark-dark vector solitons. Our analysis indicates that these self-coupled vector solitons are obtained irrespective of the intensities of the two optical beams, whereas these cross-coupled vector solitons can be established when the intensities of the two optical beams are equal. Relevant examples are provided where the photorefractive crystal is lithium niobate (LiNbO3). The stability properties of these vector solitons have been investigated numerically and it has been found that they are stable.
