Chinese Journal of Lasers
Co-Editors-in-Chief
Ruxin Li
[in Chinese], [in Chinese], and [in Chinese]

X-ray images system is a important equipment in ICF experiment. After brief survey some kinds of grazing incidence X-ray microscope used for ICF, the principles of Wolter Ⅰ X-ray microscope, and the optical system of grazing incidence soft X-ray microscope used for ICF are given.

Jan. 01, 1900
  • Vol. 28 Issue 4 359 (2001)
  • [in Chinese], and [in Chinese]

    Based on a simple theoretical model for Ti in diffused LiNbO3 optical waveguide with graded-index distribution, the optimal configuration parameters for TE/TM mode splitter of directional-coupled structure with metal clad have been obtained by using the beam propagation method. The theoretical crosstalk is less than -20.8 dB (TE mode) and -21.3 dB (TM mode) for λ=1.523 μm.

    Jan. 01, 1900
  • Vol. 28 Issue 4 362 (2001)
  • [in Chinese], and [in Chinese]

    Several Dammann phasegratings are introduced for forming specifical diffractive intensity output distributions.Simulated annealing algorithm is used to design the elements. The output characters of theelements are described and the reason of errors is analized. The elements acting as beamtransformer in metal surface laser modification are discussed too.

    Jan. 01, 1900
  • Vol. 28 Issue 4 365 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The design method and features of even-numbered Dammann gratings are presented in this paper. With numerical optimization method, 64×64 Dammann grating solution is obtained. The mask pattern is fabricated with electro-beam facilities with the feature size of 2.5 μm. The phase grating is realized with photolithographic IC technique. Three different methods to realize phase gratings are discussed. The depth of binary-phase grating measured with an atomic force microscope and the measurements of the 64×64 spot array show that the experiment is in good agreement with the theoretical result.

    Jan. 01, 1900
  • Vol. 28 Issue 4 369 (2001)
  • [in Chinese], and [in Chinese]

    The quantitative relation between visual velocity and the moving velocity of laser speckle on retina is studied. By using laser speckle a prompt and precise method to examine the focal powers of abnormal eyes is given.

    Jan. 01, 1900
  • Vol. 28 Issue 4 382 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The characteristic of Raman amplifier with coaxal broadband laser pumping has been studied. CH4 is chosen to be the active medium. The different gains of amplifier at different gas pressure and small signal gain are given. At last, the limitation of Raman amplification pumped by broadband laser beam is discussed.

    Jan. 01, 1900
  • Vol. 28 Issue 4 289 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Based on the principle of passive mode-locked laser, combining the physical characteristics of the equivalent fast saturable absorber in self-mode-locked solid-state laser, the self-mode-locked dynamic equation and rate equations for controlling the running states are presented. With making the rate equations linearized, starting condition of self-mode-locked laser is derived. The direct relation between self-mode-locked starting condition of Kerr-lens mode-locked solid-state laser and self-mode-locked starting factor is firstly presented. Theory is good in agreement with the experimental results.

    Jan. 01, 1900
  • Vol. 28 Issue 4 293 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In this paper, a flashlamp-pumped Cr:LiSAF laser system with a prism splitter to obtain dual pulse and dual wavelength laser output has been designed. The relation of laser output behaviors with input energy is studied experimentally.The time space of zero to 20 μs, and the tunable range of 860 to 920 nm for each wavelength of the dual wavelength and dual pulse laser are obtained in experiments.

    Jan. 01, 1900
  • Vol. 28 Issue 4 298 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Intracavity-frequency-doubledwith KTP, A-O Q-switched diode-side-pumped Nd:YAG laser was developed. The Nd:YAG laser was pumped by 35×15-W cw diode arrays andgenerated maximum average power of 56 W at 532nm with 10-kHz repetition rate. Theoptical-to-optical conversion efficiency and the electrical-to-optical conversionefficiency are 11% and 3.7%, respectively.

    Jan. 01, 1900
  • Vol. 28 Issue 4 301 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Under the condition of given pump laser energy, using a lens with short focal length to focus the Cr:LiSAF electrooptical Q-switched laser pulses into CS2 SBS-cell, the backward SBS scattering of broad-band and multi-transverse-mode Cr:LiSAF laser pulses is realized, and the effective pulse width′s compression is observed.

    Jan. 01, 1900
  • Vol. 28 Issue 4 304 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Using a uncoated bulkperiodically poled LiTaO3 with the period of 7.81 μm to double the frequency of a diode-pump Q-switched Nd:YVO4 laser is studied.The laser is with a 60 ns pulse duration, 10 kHz repetition rate. Internal conversionefficiency is 13.5% when pump power is 193 mW. The second-harmonic power as the functionof crystal temperature is also measured, which is agreement very well with the theory. Thephase matching temperature is 36.1℃.

    Jan. 01, 1900
  • Vol. 28 Issue 4 307 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Self-Q-switched Er-dopedfiber laser has been studied in this paper. Er-doped fiber is applied as gain medium,which is pumped by CW 980 nm LD. A fiber grating is used as the wavelength selector andcavity reflector. The stable self-Q-switched laser output is realized based on thenonlinearity of SM fiber―stimulated Brillouin scattering. The repetition rate about 64.5MHz, and the full width at half maximum (FWHM) about 2.2 ns are obtained.

    Jan. 01, 1900
  • Vol. 28 Issue 4 310 (2001)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A novel multi wavelength erbium-doped fiber ring laser is presented, which employs a novel comb filter based on a fiber Bragg grating asymetriclly written in a Sagnac interferometer. The filter has advantageous of simple design and fabrication, low cost and low insertion loss. Stable triple-wavelength and dual-wavelength laser operations with wavelength spaces of 0.34 nm and 0.5 nm, respectively, and output power differences of <2 dB and <0.4 dB, respectively, have been demonstrated.

    Jan. 01, 1900
  • Vol. 28 Issue 4 313 (2001)
  • [in Chinese], and [in Chinese]

    From energy balanceequation, using micropiece analytical method, heat balance equation for high power fastaxial gas flow CO2 laser tube is established. To practical fast axial CO2 laser, thetemperature distribution of fast flow laser tube from solving the heat equation isderived. The curves for the temperature distribution are given and the result isdisscussed.

    Jan. 01, 1900
  • Vol. 28 Issue 4 317 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The monolithic single ridge stripe electroabsorption modulated DFB laser (EML′s) fabricated by selective area LP-MOVPE is reported. The threshold current of the EML′s is 26 mA; the maximum output power is about 9 mW; the extinction ratio is more than 16 dB; no wavelength shift with modulator bias is observed from the ASE spectrum after the optical feedback being reduced; the capacitance of the modulator part is 1.5 pF. No obvious changes of threshold current, isolation resistance and extinction ratio are observed after the preliminary aging test. The EML′s can be used in the 2.5 Gb/s long haul fiber communication systems.

    Jan. 01, 1900
  • Vol. 28 Issue 4 321 (2001)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A study of equivalent circuit model of MQW lasers derived from three-level rate equations is carried out. It can explain the carrier distribution, which can not be explained by traditional two-level model. The simulation of modulation behavior is implemented in SPICE. Results of various modulation properties from the simulator are discussed. Especially, the scheme was implemented in a hierarchic way, which provides a much easier management and a help to realize photonic design automation (PDA).

    Jan. 01, 1900
  • Vol. 28 Issue 4 325 (2001)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    By using the numerical solution of time-dependent Schrodinger equation for a hydrogen atom, the coherent control of ionization in two-color laser fields, with considering a fundamental laser field mixed with its second harmonic field or its third harmonic field is investigated. Comparing the two scenarios, it is found that the ionization rates of the system are quite different due to the different superposition effects of the two kinds of combinations.

    Jan. 01, 1900
  • Vol. 28 Issue 4 330 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A new type of π-conjugated polymer―Polypyrrylarylenemethine is designed and synthesized, which shows large nonlinear optical characteristics. It is discovered in experiment that as the 526 nm TEM00 laser beam passing through the Polypyrrylarylenemethine/N-Methyl-2-pyrrolidone (NMP) solution, numbers of concentric diffraction rings arise in far field. This phenomenon can be explained by the spatial self-phase modulation of the Gaussian beam passing through the nonlinear medium. With theoretical analysis and numeric calculation, it is found that the transverse nonlinear phase shift caused by the sample can be very well fitted by a Gaussian function. The nonlinear refractive index n2 can be estimated according to the number of the diffraction r ings. The n2 of Polypyrrylarylenemethine/NMP solution is about -1.85×10 -3 esu.

    Jan. 01, 1900
  • Vol. 28 Issue 4 333 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    With the Fresnel diffraction theory and Collins equation, the propagation of power spectral density (PSD) of wave-front with random phase is studied. The theoretical analysis for the propagation of PSD in some typical optical system is concerned, and the digital simulation results are also given.

    Jan. 01, 1900
  • Vol. 28 Issue 4 337 (2001)
  • [in Chinese], [in Chinese], and [in Chinese]

    The dynamical propertiesof two spatially coupled, non-identical solid state lasers are analyzed. When both of thelasers are pump-modulated with different losses, the output intensities of the two lasersshow periodic motion, chaotic motion, chaotic synchronization and loss of synchronization.The occurrence of synchronization of chaotic lasers is related to the coupling between thetwo lasers. When the coupling is strong, the periodic motion occurs. For intermediatecoupling, there appears chaotic motion. Chaotic synchronization may occur under certaincondition. When the coupling is weak, the two lasers oscillate almost independently.

    Jan. 01, 1900
  • Vol. 28 Issue 4 343 (2001)
  • [in Chinese], and [in Chinese]

    Based on the beampropagation equation in free-space, the hyperbolic-fit mothed is used to calculate theM2-factor of Gaussian beams passing through a spherically aberrated lens. Meanwhile, thepower in the bucket (PIB) at the geometrical and real focal planes of Gaussian beams withspherical aberrations is also studied. Both M2-factor and PIB are chosen as the criterionfor charactering laser beam quality, detailed numeri cal calculations are performed toillustrate the effect of the spherically aberr ated lens on laser beam quality. Theresults obtained in this paper would be useful for some practical applications.

    Jan. 01, 1900
  • Vol. 28 Issue 4 347 (2001)
  • [in Chinese], H. Y. Tam, S. L. Ho, and W. H. Chung

    A new approach for simultaneous strain and temperature measurement using a single fiber Bragg grating has been reported in this paper. The fiber Bragg grating used for simultaneous strain and temperature measurement is written on the joint of two different fibers, and has two reflection-peaks at different wavelength, which have different temperature response because of the different thermo-optic coefficients for the two fibers. By measuring wavelength shift of the two peaks, strain and temperature can be determined simultaneously.

    Jan. 01, 1900
  • Vol. 28 Issue 4 372 (2001)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A novel displacement remoter measurement utillizing Dopples effect was proposed in this paper. The Doppler shift of differential structure was analyzed theoretically. The double-beam differential optical system with a optical-acoustic modulating structure, big aperture collecting backward scattering light, and compensating the losing signal by computer tracking software was designed. The displacement measurement of paper and rough mental surface at a distance of 10 meters has been achieved with an accuracy of ±0.5%.

    Jan. 01, 1900
  • Vol. 28 Issue 4 375 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Hexagonal symmetry microstructure and rectanglar symmetry microstructure were fabricated successfully on the azobenzene polymer films. The experimental results indicate that the symmetry of the microstructures has been controlled on the base of the simple theory, and it is pointed out that the lattice constants of the microstructure can also been controlled easily. The method to fabricate periodic microstructures with novel mechanism has potential applications in the future.

    Jan. 01, 1900
  • Vol. 28 Issue 4 379 (2001)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The relationship between the length of optical fiber time delay line and characteristics of periodical fluctuation affixed on homodyne spectrum is analyzed. Using this method, the output linewidth of active optical fiber ring resonator filter is measured. Experiment results are consistent with the theoretical model.

    Jan. 01, 1900
  • Vol. 28 Issue 4 351 (2001)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    This paper presents theexperimental research of a new large aperture slab amplifier. The structure of theamplifier is also introduced. With a multi-probe system, the gain uniformity over the slabclear aperture is tested. Experimental results under different pumping conditions indicatethat the gain uniformity over the slab clear aperture is about 1.06:1 at the normal voltage of 22 kV.

    Jan. 01, 1900
  • Vol. 28 Issue 4 355 (2001)
  • Please enter the answer below before you can view the full text.
    Submit