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1.
A new type of axisymmetric-fold-combination CO2 laser, which is constituted by several axisymmetric four-mirror cavities, is studied theoretically in this paper. The mutual energy coupling occurring within the communal discharge region of the unstable resonator to inject seed signals into each sub-resonator is demonstrated by theoretical deduction. The numerical results have proved that phase-locking could be achieved in this cavity, and the beams with phase-locking have both a higher intensity and a smaller light spot than the ones without phase-locking. 相似文献
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Based on the phase-locking principle of Gaussian beam, the phase-locking mechanisms of the spherical wave from axisymmetric concentric cavity (ASCC) CO2 laser are analyzed. And then we study the variety laws of the equiphase surfaces and the light spots of the injected beam. The numerical calculations show that the injected beam could be considered as a spherical wave approximately in the ASCC. The phase-locking of the spherical wave is different from the phase-locking of the Gaussian beam; there are different field distributions between Gaussian beam and spherical wave. And the phase-locking method could improve the maximum value of the light intensity, the encircled energy reflects the degree of phase-locking. 相似文献
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A method of reflection-injection phase-locking used on two-dimensional axisymmetric-fold combination resonator (ASFC) CO2 laser has been proposed. The structure characteristics and the method of phase-locking have been introduced. The expression of output light intensity distribution has been deduced by matrix theory and Collins Formula and the output light intensity distribution has been numerically calculated and simulated. Comparing the output light intensity distribution in the case of phase-locking with that of non-phase-locking. The result shows that this method of phase-locking greatly improve the characteristics of output beam. 相似文献
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A new type of laser resonator that is designed to extract good phase coherence and circular beams from an annular gain region is developed. We also calculated the parameters theoretically by applying the resonator to a CO2 laser. And the transfer characteristics of the output beam from the phase-locking laser resonator through a lens are also discussed. 相似文献
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The frequency modulation of the two-dimensional (2D) axisymmetrical folded and combined (ASFC) CO2 laser is performed by a blazed grating. Its principle of phase-locking is studied in detail. The properties of the injected mode in ASFC and the mode coupling coefficient, which are analyzed, will be considered to be the main factors of the phase-locking. It is shown that the effect of phase-locking will not be influenced when the blazed grating is adjusted. However, it will influence the distribution of the light intensity to some degree. 相似文献
7.
Xiao Huang Jiayin Qin Xingshi Zheng Yanxiang Bao Xizhang Luo Yikun Lin 《International Journal of Infrared and Millimeter Waves》1997,18(8):1539-1546
By solving the density matrix equations of a quantum system, the output power intensity of an optically pumped CH3OH FIR laser (CH3OH-OPFIRL) was calculated by means of iteration method, and the spectral characteristics were got. Base on the calculation,
optimization of operating parameters including operating gas pressure, pumped power and output coupling coefficient of the
CH3OH cavity laser were systematically studied. Experimental, a series of FIR emissions of the CH3OH cavity laser pumped by TEA-CO2 laser with 9P(16) line were measured. The experimental results were in good agreement with theoretical calculations.
The project was supported by the Special Research Foundation of Doctorate Station in University of P.R.C. 相似文献
8.
The theoretical investigation of the superconducting state properties viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T C, isotope effect exponent α and effective interaction strength N 0 V of ten binary CuCZr100-C (C = 25–60 at%) metallic glasses is performed, using Ashcroft’s empty core model potential. Five local-field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used to study the screening influence on the aforesaid properties. It is shown that the electronphonon coupling strength λ and the transition temperature T C are quite sensitive to the selection of the local-field correction functions, whereas the Coulomb pseudopotential μ*, isotope effect exponent α and effective interaction strength N 0 V show a weak dependence on the local-field correction functions. The values of T C obtained from the H-local-field correction function are found to be in qualitative agreement with available theoretical or experimental data and show almost linear behavior with respect to the concentration C of Cu. The present results are shown to be in good agreement with other available theoretical or experimental data. The obtained results confirm the existence of the superconducting phase in the metallic glasses. 相似文献
9.
In this paper,experimental and theoretical studies of the output mode characteristics of an in-phase locked gain waveguide array CO 2 laser are reported.The experimental results of the optical oscillation mode frequency,the far-field intensity distribution and the burnt pattern of the sliced waveguide array laser are obtained.A revised mode expression of the rectangle waveguide,which is suited for this waveguide array CO 2 laser,is proposed.The theoretical simulation results based on the revised mode expression are shown to be in good agreement with the experimental results. 相似文献
10.
The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd:YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse the influence of fractional thermal loading on the thermal effect in the Nd:YVO4 laser based on finite element analysis. The thermal focal lengths and the end-surface deformations of laser rods in Nd:YVO4 quasi-three-level and four-level lasers are measured and compared with the results obtained by ordinary interferometry for the demonstration of higher thermal loading in 914-nm laser. Finally the fractional thermal loading in the Nd:YVO4 quasi-three-level laser is calculated by matching the experimental and the simulated end deformations. 相似文献
11.
In this work, the complete matrix of optical spectral levels in trigonal symmetry of 3d2 (3d8) ions are established on basis of strong field coupling mechanism by using two spin–orbit coupling parameters model. The contribution of the spin–orbit coupling of ligand to the optical spectra has been included in these formulas. As an application, the optical spectra of Cr4+ in Y2Ti2O7 and Y2Sn2O7 have been studied by the complete diagonalization (energy matrix) method. The covalent effect has been studied and the difficulty about Dq parameter in explanation of optical spectra of Cr-doped Y2Ti2O7 and Y2Sn2O7 is removed. The theoretical results are in good agreement with observed data. 相似文献
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分别利用速率方程理论和六温度模型理论对Q开关CO2激光器动力学过程进行了理论分析比较,实验上测得电光调Q射频波导CO2激光器脉冲激光建立时间及峰值功率与速率方程理论和六温度模型理论计算结果一致.但速率方程理论计算的激光脉冲宽度较“窄”,并且几乎没有拖尾,而六温度模型理论计算的脉冲激光波形有明显的拖尾,符合实际测量的波形.另外,六温度模型理论可以全面反映激光器工作气体中不同分子能级的能量转移过程,因此六温度模型理论分析更全面
关键词:
2激光器')" href="#">电光调QCO2激光器
六温度模型理论
速率方程理论 相似文献
15.
M. Ingusio A. Moretti G. Moruzzi F. Strumia 《International Journal of Infrared and Millimeter Waves》1981,2(5):943-986
An extensive theoretical and experimental analysis of the absorption and emission spectrum of a CH3OH FIR-laser excited by a conventional CO2 laser is presented. Particular interest is devoted to the Stark shifts of the pump and lasing lines and to the electric field dependence of the Fir-laser output of the various lines. The offsets with respect to the exciting radiation and the Stark shifts of the IR absorption (pump) lines are measured by means of the transferred Lamb dip technique. The theoretical behaviours of the Stark patterns are calculated for several choices of the quantum numbers and selection rules involved in the transitions. A large variety of experimental results are reported and compared to theory. Non-linear Stark shifts have been observed for the 37.5m FIR laser line and for the IR-pump transitions excited by the 9-P(38) and 10-R(38) CO2 laser Lines. Line assignments are proposed and new FIR laser lines are reported. 相似文献
16.
Zhou Tiege Mao JingCui Hanlin Zhao XinjieFang Lan Yan Shaolin 《Physica C: Superconductivity and its Applications》2009,469(13):785-788
We propose a new model of a Josephson junction array embedded in a resonant cavity. The model considers the excitation of the resonance mode by the array and the influence of the resonance mode on the array. The phase-locking properties of the junction array are investigated in the frame of the model. Resonant steps in the current–voltage characteristics due to the interaction between the array and the resonant cavity and many other features of the phase-locking behaviors have been produced. The results include the influence of the quality factor, the strength of the coupling, as well as the junction number of the array on the phase-locking properties. The model can successfully explain many features of the real situation and provide useful new predictions. 相似文献
17.
Ping Li Qingpu Wang Xingyu Zhang Yurong Wang Shichen Li He Jingliang Lu Xingqiang 《Optics & Laser Technology》2001,33(6)
A diode-pumped Nd:YVO4 laser passively Q switched with GaAs is studied theoretically and experimentally. We have demonstrated the influence of single-photon absorption, two-photon absorption and free-carrier absorption in GaAs on the Q-switched pulse characteristics. The pulse profile, pulse energy and pulse width of the Q switching with GaAs are simulated by using the conventional rate equations of the four-level laser system. The experimental results show reasonable agreement with the theoretical results on the whole. 相似文献
18.
Diffraction effect of the injected beam in axisymmetrical structural CO2 laser is studied based on the injection-locking principle. The light intensity of the injected beam at the plane where the holophotes lie is derived according to the Huygens–Fresnel diffraction integral equation. And then the main parameters which influence the diffraction light intensity are given. The calculated results indicate that the first-order diffraction signal will play an important role in the phase-locking when the zero-order diffraction cannot reach the folded cavities. The numerical examples are given to confirm the correctness of the results, and the comparisons between the theoretical and the experimental results are illustrated. 相似文献
19.
White light interferometer can be used to measure the amplitude extinction ratio (ER) of polarizer and coupling distribution in fiber. A LiNbO3 polarizer coupled with a polarization maintaining fiber and a silica planar waveguide at the two ends was measured using white light interferometer. According to the principles of optical coherence domain polarimeter (OCDP) technique, the test scheme is analyzed and presented to measure the ER of LiNbO3 polarizer with its apparatus proposed correspondingly. By analyzing the interference intensity, both the ER of LiNbO3 polarizer and its coupling crosstalk with optical fiber and waveguide are obtained. The results illustrate that the ER of a 5 mm-long LiNbO3 polarizer is 71 dB and the crosstalk of the coupling points are around 40 dB. The results have good agreement with analysis. 相似文献
20.
A comprehensive theoretical analysis of optimization of gain in CO2-N2 gasdynamic laser employing wedge or conical or hyperbolic nozzles with either H2O or He as the catalyst is presented. After a review of previous work, the usual governing equations for the steady inviscid
quasi-one-dimensional flow in a supersonic nozzle of a gasdynamic laser are used to obtain similar solutions for the various
flow quantities, which variables are subsequently used to optimize the small-signal gain on theP(20) line of the (001) → (100) transition of CO2 at wavelength 10.6μm. The corresponding optimum values like reservoir pressure and temperature and nozzle area ratio also have been predicted
and presented in the form of graphs. The analysis predicts that employing of 2D-wedge nozzle results in higher gain values and the CO2-N2-H2O gasdynamic laser employing 2D-wedge nozzle is operationally the best laser system for which the optimum value as high as 3.1 m−1 gain can be obtained. 相似文献