Acta Optica Sinica
Co-Editors-in-Chief
Qihuang Gong
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

Properties and conditions of the propagation of sech and Gaussian type quasi-soliton in optical fibre link with periodical dispersion management and power balance are discussed by variational method. Criteria of the optimal design are given. In accordance with the criteria, numerical simulations are made and the results show that the approximate calculations play a significant role in the system design.

Jan. 01, 1900
  • Vol. 19 Issue 10 1297 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    The analysis expression of width of chirped Gauss pulses transmission in fiber after being reflected by chirped fiber grating is given. Based on it, several important problems on pulse compression and dispersion compensation are discussed. As examples, linearly chirped fiber gratings are calculated by numerical method. It is found that pulses are broaden symmetrically in fiber. A simple way to estimate the width of pulses reflected by fiber grating is presented.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1305 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    Based on the wave theory of light and considered the polarizations of signal and crosstalk sources, the bit error rate and power penalty of an arrayed-waveguide grating multiplexer are calculated using the improved saddlepoint approximation. The calculated result agrees well with the result of Gauss approximation and experiment, and shows high calculation precision of the improved saddlepoint approximation.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1310 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The erbium doped fiber amplifier (EDFA) gain flattening filters were fabricated by writing long period gratings in hydrogen-loaded standard single-mode fibers using amplitude masks and a properly designed program controlled scanning exposure system. The gain variation of ±3 dB in an EDFA is reduced to ±0.3 dB over a bandwidth of 30 nm and the total extra insertion loss of the device is less then 0.3 dB.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1315 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    In phase-measuring profilometry (PMP), a new simultaneous calibration algorithm of phase-shifting based on fast Fourier transform (FFT) is presented. The current phase shifting is calculated with the help of the information of a additional fringe pattern and a FFT modulation mask. With this algorithm, the moving of the project grating can be controlled accurately and simultaneously, the accuracy and the automation of the measuring system are improved greatly.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1390 (1999)
  • [in Chinese], and [in Chinese]

    A new technology of digital speckle photography is presented. It combines the CCD with a computer. By using a quick processing algorithm the whole field information is obtained directly, the Fourier transform and coherent laser is abandoned in this technology.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1396 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A 3D digital imaging system based on white-light digital moire is presented. The system makes use of incoherent illumination and a spatially digital phase-shift algorithm as well as an efficient phase unwrapping algorithm with the composite-template construction technique. In addition, an approach to the determination of optical geometry sensitivity is given from which the 3D digital image of surface topography can be obtained. The 3D digital image made on a human face as an experimental result is shown.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1401 (1999)
  • [in Chinese], and [in Chinese]

    A nature texture classification method based on fractal dimension using self-similar texture characterization is presented. For this purpose, eight fractal dimensin (FD) features are used based on the original image, the high gray level image, the low gray level image, four directional (0°, 45°, 90°, 135°) gradient image and the multi-fractal dimension of order two. The fractal dimension is estimated with the modified box-counting method. The texture classification is completed with back propagation (BP) neural network. The results are compared with other techniques. The Wiener filter is used to improve the performance of this method.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1406 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    The phase errors, resulting from the multi-beam interference in the Fabry-Perot cavities of the wavelength scanning fiber-optic interferometer for absolute distance measurement, are analyzed. It′s proved that selecting the suitable reflectivities of two F-P cavities and the length of the reference cavity can reduce the phase errors. In authors′ system, the optimal cavity reflectivity is in the range of 0.10~0.15 and the reference cavity length is about 0.95 mm, the accuracy of 0.05 μm can be obtained in the range of 1 mm.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1361 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    The characteristics of an acousto-optical modulator (AOM) with cross-talks among its diffracted beam are proposed and verified theoretically and experimentally. The cross-talks cause intensity modulation items and the frequencies are harmonics of the driving frequency in each diffracted beam. The drift of the incident beam on an AOM will cause a frequency drift in its diffracted beams. The influences on the measuring accuracy of an AOM heterodyne interferometer are analyzed in detail. Methods to eliuminate the influences are proposed and identified: employing two AOMs and obtaining its reference signal from the interferometer. The AOM heterodyne interferometer can be used in the case of the accuracy beyond nanometer.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1368 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The theory of temperature and density measurements of air flow by Rayleigh scattering and UV (193 nm) laser-induced oxygen molecules fluorescence (LIF) are studied. This method befits to instantaneous two-dimensional temperature and density measurements of air and Oxygen flow. The Rayleigh scattering of room air as well as oxygen flow LIF image are observed by an intensified CCD videocamera (ICCD) system. The two-dimensional flow parameter is obtained after image process.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1375 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The basic principle of parallel confocal detecting method is proposed. With the 3-D point spread function and the matrix operating form, the mathematical model of 3-D detecting process based on the method is established, which has a higher theoretic value and a wider suitability due to the involvement of the general confocal and non-confocal detection. Meanwhile, the conclusion of theoretical analysis shows that the optical detection of parallel confocal method conforms to the multiplication form of two point spread functions, which is the fundamental characteristic of confocal detection.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1381 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    An Optical Coherence Tomography (OCT) system is developed. The properties and experimental results of the OCT system are analyzed. Some factors that affect the property of the system are studied and some improving ideas are presented.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1386 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The theory of dispersion compensation using single prism is developed. The effectiveness of this theory and stable self-mode-locked operation using single prism and two single prisms are demonstrated in experiment.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1318 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    With a type-Ⅰ noncritical phase-matched LBO crystal as the intracavity frequence doubler in a LD pumped Nd:YVO4 laser, 240 mW of 671 nm laser output was obtained with 5.44 W absorbed pump power, the optical-optical conversion efficency is 4.4%.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1323 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A short cavity Er/Yb fiber grating laser is demonstrated. Its resonant cavity is composed by two Bragg gratings which were UV written directly on a 30 mm photosensitive Er/Yb fiber. The two gratings were ~6 mm and 10 mm long, with 90% and 98.6% in reflectivity, 0.28 nm and 0.26 nm in 3 dB bandwidth, respectively. Pumped by a 980 nm diode laser, the associated fiber grating laser exhibits 8 mW thershold, ~14% slope efficieny, 30 dB polarisation mode suppression ratio. About 6 mW output power and 61 dB signal to noise ratio were obtained upon the maximum 50 mW 980 pump power in the experiment.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1327 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    A novel type of resonater output mirror referred as reflectivity-variable-with-wavelength mirror (RVWM) has been fabricated and tested. Its efficiency, and some temporal characteristics of tunable laser has been greatly improved.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1332 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    The first quasi-cw mode locked laser diode pumped Cr:LiSAF laser was demonstrated in China. Pumped by AlGaInp laser diode emitting near 670 nm, 4 mW CW output at 850 nm was obtained when the absorbed pumped power of 368 mW. In quasi-continous wave operation, the femotosecond pulse was obtained at 850 nm with Neocyanine dye.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1337 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The theory of calculating the coupling losses in a coaxial waveguide laser resonator is introduced. Computations of the coupling losses for some TE modes of an annular waveguide, as a function of mirror curvature and position, are presented in the limit of large mirror aperture. It is shown that there exist three special configurations contributing to low coupling losses.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1341 (1999)
  • [in Chinese], and [in Chinese]

    The stable condition of multi-wavelength optical cavities is discussed by the method of ray-pulse matrices, and the formula of net GVD is deduced. As an example, a novel self-mode-locked cavity is analyzed and the magnitude of GVD is calculated. These conclusions are very useful for understanding the mechanism of mode-locking.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1347 (1999)
  • [in Chinese]

    The nonlinear optical properties of F-P cavity with a second order nonlinear crystal inside are discussed according to the effective third order susceptibility, which is formularized by the cascaded second-order processes in nonlinear crystal in small signal conversion condition. The analysis shows that the power density passing through the nonlinear crystal is several ten times higher than input power density. Enhanced nonlinear phase shift is changed with wave vector mismatch. The maximum phase shift of fundamental beam is observed when the wave vector mismatch is near 2π. This phase shift is changed with input power density, second order susceptibility and length of nonlinear crystal.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1354 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    A novel push-pull azo dye-doped polymer film has been developed for write-once optical recording. The absorption spectra of the spin-coated thin films show a strong and broad absorption region at 400~550 nm, which matches well with the wavelength of Ar+-laser. The optical recording performance of the azo dye-doped polymer thin films shows that higher reflectivity contrast can be obtained at lower writing power and writing pulse width using the Ar-+-laser (514.5 nm) irradiation. These results demonstrate that the single layer of azo dye-doped PMMA thin film is a promising candidate for short-wavelength optical recording.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1411 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The nonlinear optical properties of 1-(2-pyridylazo)-2-naphthol film were studied by using Z-scan technique with ps pulse laser at 532 nm. Under the condition of the lower input pulse enrgy, the resonance third-order nonlinear susceptibility χ(3)R and nonlinear absorption coefficient β were measured to be 1.29×10-9 esu and 42 cm/GW, respectively. The nonlinear absorption responding to the pulse energy was studied and it was found that the reverse saturable absorption turns into the saturable absorption with the increasement of pulse energy.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1415 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    Three calculating methods for oxide-glasses infrared optical constants including refractive index nr and extinction coefficient k were discussed using numerical analysis, geometrical optics and electromagnetic theory. A simple method was deduced for calculating refractive index and extinction coefficient. It provides a useful way for study of the infrared oxide-glass materials.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1420 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Red ZnS:Sm, Cl thin film electroluminescent devices with ceramic thick film as insulator layer have been manufactured. The transparent electrode is ZnO doped with Al made by sputtering and the emitting layer is ZnS:Sm, Cl made by electric evaporation method. The electroluminescent spectrum of ceramic subsrrate thin film electroluminescent (CSTFEL) device has been measured. The dependence of brightness on voltage was measured and the dependence of efficiency on voltage was calculated. The CSTFEL device was driven under 50 Hz and the maximum luminance is 18.4 cd/m2 and the maximum efficiency is 0.06 lm/W.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1430 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The initial coating design in the coating optimization is discussed, especially, the initial design in Needle method and an amelioration of Needle method is presented. It begins from the same thickness of single layer to work out the optimum design in the way of automatically revising the initial thickness by controlling the value of the merit function.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1433 (1999)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Jan. 01, 1900
  • Vol. 19 Issue 10 1437 (1999)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Jan. 01, 1900
  • Vol. 19 Issue 10 1439 (1999)
  • [in Chinese], [in Chinese], and [in Chinese]

    Based on colorimetric theory, the present study has made a thorough analysis of color variable Y and presented a new method of subjective matching of heterochromatic brightness using Munsell color system. It was pointed out that the Munsell equality V section does not comform the characteristics of human vision, and the linear relation between Munsell V and subjective brightness was established through experimental and theoretical analysis.

    Jan. 01, 1900
  • Vol. 19 Issue 10 1426 (1999)
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