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

A new kind of cylindrical lens array (CLA), named as hybrid element cylindrical lens array (HECLA), which composed of a few whole elements and two half elements, is proposed in this paper. The intensity distribution along the focal line formed by HECLA-target line focusing system with quasi-four-element and quasi-five-element is calculated. The results show that the using of HECLA is able to improve the intensity uniformity along the focal line greatly. For example, the modulation index decreased to 1.7% for quasi-five-element HECLA in the case of super-Gaussian distribution laser incident.

Jan. 01, 1900
  • Vol. 27 Issue 6 505 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    128×128 diffractive microlens arrays have been designed by considering the relative optical and processing parameters for 3~5 μm wavelength with a microlens diameter of 100 μm. The lens F number and array pitch are f/1.5 and 100 μm, respectively. The diffractive microlens arrays have been fabricated on the surface of Si substrates by successive photolithography and Ar+ ion-beam-etching technique. The practical processes and fabrication method are discussed. The optical characteristics and measurement of the surface relief structure are presented.

    Jan. 01, 1900
  • Vol. 27 Issue 6 510 (2000)
  • [in Chinese]

    Errors of the diffractive linear laser diode astigamation-free collimator are analyzed in the paper. The errors of the home made collimator are calculated. The ways for reducing the errors are proposed.

    Jan. 01, 1900
  • Vol. 27 Issue 6 515 (2000)
  • [in Chinese], and [in Chinese]

    An approximate method, by properly choicing the effective grating separation in order to compensate for the spherical aberration in the grating stretcher with a telescope system is proposed. Formula about the modification for the group velocity dispersion and the fourth order dispersion is presented. According to the formula, some demands on the quality of the component are given.

    Jan. 01, 1900
  • Vol. 27 Issue 6 519 (2000)
  • [in Chinese], and [in Chinese]

    The influences of the fast gain saturation and the length of SOA on the performances of terahertz optical asymmetric demultiplexer (TOAD) are investigated in this paper. Two operation modes, small width switching window mode and large width switching window mode, are all analyzed. It is found that the fast gain saturation has great influences on both the shape of switching window and the switching energy, and the dependence of the switching energy on the control pulse width are completely different for the two operation modes. In addition, we find that effect of SOA length can greatly reduce the amplitude of the secondary switching window, which indicates that by properly choosing the length of SOA, the switching window width can be reduced and the speed of TOAD can be increased.

    Jan. 01, 1900
  • Vol. 27 Issue 6 525 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The effect of various factors on axial resolution in confocal scanning microscopy is discussed, and some preliminary experimental results are given. Possible approaches for axial resolution optimization are also demonstrated.

    Jan. 01, 1900
  • Vol. 27 Issue 6 531 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A solid-stated laser with the direction prism end reflector was developed. The end reflection maladjustment angle of ±20°is promised. The beam divergence angle is of 1.6 mrad. The laser field belong to lower order mode. Then, this laser has high stability, high beam quality and anti-maladjustment function. The theoratical analyse of the resonator characteristics is described.

    Jan. 01, 1900
  • Vol. 27 Issue 6 537 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    “Peak crosscorrelation scan re-registration” algorithm aiming at the recovery of the distorted OCT images is proposed in this paper. The image distortion related factors are analysed theoretically. Digital filtering allows the distortion information to be derived from the peak crosscorrelation functions. A gray threshold is set to avoid the influence of the noise in crosscorrelation. To reduce unexpected misregistration induced re-registration fault, the maximum value of re-registration is limited, as a result the fault-tolerance of the algorithm is greatly improved. In addition, the paper also gives the distorted images and the restored ones, together with the suggestions to decrease the cumulating errors of the algorithm.

    Jan. 01, 1900
  • Vol. 27 Issue 6 555 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The coupling of two mutually incoherent beams of extraordinary polarization of degenerate wavelengths in the forward direction in photorefractive Ce:KNSBN crystal is theoretically analyzed and experimentally demonstrated. The bright and dark rings due to coupling of two incoherent beams were observed and a new method of fanning reduction by using incoherent erasure are proposed in photorefractive crystal.

    Jan. 01, 1900
  • Vol. 27 Issue 6 561 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A novel volume holographic wavelet correlator with multi-input channels is proposed and constructed in this paper without adding any component. The method of input plane shift and the technique of angle multiplexing are combined besides the introduction of wavelet transform. Multi-input images can be recognized simultaneously according to a system output. Its application in human face recognition is studied, and experimental results are given.

    Jan. 01, 1900
  • Vol. 27 Issue 6 567 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    43 patients were received fluorescent diagnosis induced by small dose of hematoporphyrin (2 mg/kg). 35 of them were cancered. The rest were non-cancered. By recording and analyzing the spectrum of fluorescence with optical multichannel analyser (OMA), managing the data, it was found that the fluorescence intensitics were 1.18±0.13 for cancered patients, 1.00±0.06 for non-cancered patients. Using the floor level of the formar 1.05 as tumor diagnosis criterion, the positive rate was 91.4%.

    Jan. 01, 1900
  • Vol. 27 Issue 6 572 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A maximum of 8.8W of cw TEM00 mode output at 532 nm has been obtained by intracavity frequency doubling with KTP in a Nd:YVO4laser doubly-pumped with 28 W diode pumping power. The optical-optical conversion efficiency is 31.5%. The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO4laser is discussed. The Nd:YVO4laser has good power stability.

    Jan. 01, 1900
  • Vol. 27 Issue 6 481 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    A simple Nd:YVO4 microchip laser with a plano/plano cavity end-pumped by LD is reported. The laser output with λ=1.064 μm is TEM00 mode. Pumping threshold is 40 mW with a slope efficiency of 29.4%. The experimental set-up and results are discussed in this paper.

    Jan. 01, 1900
  • Vol. 27 Issue 6 485 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The external-cavity semiconductor laser with fiber Bragg grating (FBG) as its mode selector is an important source with stable and controllable lasing wavelength. This paper describes the key technologies of its fabrication, mainly on FBG itself, AR coating of the chip, fiber coupling and pachaging. The primary results of the laser are also given.

    Jan. 01, 1900
  • Vol. 27 Issue 6 488 (2000)
  • [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Some novel methods to get the optical pulses at repetition rate (fp) integer multiples of the RF drive frequency in actively harmonic mode-locked erbium doped fiber laser (AHML-EDFL) are reported. The character of the nonlinear modulation is analysed. The mechanism of high-repetition rate pulses generated from AHML-EDFL in particular, the influence of modulation degree on pulse train are discoussed.

    Jan. 01, 1900
  • Vol. 27 Issue 6 493 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Optical resonator effect is observed around 260 nm central spectral region using high current relativistic electron beam to pump pure argon transversely, and it is indicated that electron beam pumping with both steep rise time and high current relativistic electron beam is an important condition for realization of optical resonator effect around this central spectral region.

    Jan. 01, 1900
  • Vol. 27 Issue 6 542 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    Interference phenomena between high harmonics and hyper-Raman lines in strongly driven two-level atomic system has been investigated. It is shown that the hyper-Raman lines disappear, the background noises are restrained and the high harmonics are enhanced due to the interference effect.

    Jan. 01, 1900
  • Vol. 27 Issue 6 547 (2000)
  • [in Chinese], [in Chinese], [in Chinese], and [in Chinese]

    The preparation of Tm:BaY2F8powders and the up-conversion luminescence of Tm:BaY2F8are reported in this paper. Excited by red light of 650 nm, two violet luminescence with peaks at 417 and 430 nm and the blue luminescence with peaks at 458 and 470 nm were observed. According to the spectral data reported here, the energy level scheme of Tm:BaY2F8was given, and the mechanism of the up-conversion luminescence was suggested.

    Jan. 01, 1900
  • Vol. 27 Issue 6 551 (2000)
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