共查询到20条相似文献,搜索用时 203 毫秒
1.
由于Nd:磷酸盐玻璃的热导率和破坏阀值都比较低,故连续波锈模钕磷酸盐玻璃激光器要求其谐振腔有特殊的设计.本文在谐振腔长度固定的限制下,分析了三元件式谐振腔的特性,并且讨论了连续波主动锁模Nd:磷酸盐玻璃激光器光学谐振腔的设计.我们讨论了在不同参量范围下谐振腔的稳定性范围和特性,并且阐明了有关的最佳参数的范围.给出了谐振腔最佳运转区参数的解析表达式.实验结果与理论预测符合得很好.这个解析式对设计三元件或多元件的任何端面泵浦和锁模谐振腔是很有用的. 相似文献
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Crossed waveguide is widely used in optical devices, whose excess loss has a strong impact on multi-turn optical waveguide ring resonator and resonator integrated optic gyro. The resonance curve of the ring resonator is sharply dependent on the loss within the resonator. This paper presents how to get excess loss of the crossed waveguides nondestructively through the comparison of the resonance characteristics between one-turn and multi-turn optical waveguide ring resonators. 相似文献
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The ideas of generating surface whispering gallery mode (SWGM) through coating a microresonator with a layer of metamaterials is proposed in our previous work. In this paper, we verify the SWGM with a square resonator based on two-dimensional LC network in radio frequency band. The equivalent node voltage distribution matrix of this resonator is derived. Results show that node voltage can be amplified when the square resonator is covered with a layer of double negative metamaterials. The performance of the metamaterial resonator as a dielectric sensor with excellent sensitivity has been demonstrated. This work may put a great step toward the realization of SWGM sensors using metamaterials. 相似文献
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Michael Raum 《International Journal of Infrared and Millimeter Waves》1999,20(11):1859-1874
A ring resonator design for optically pumped submillimeter wave (SMMW) lasers using the same set of four mirrors (including one focussing mirror) for pump beam and SMMW beam guiding is introduced.The optimum design is discussed on the example of a 2.523 THz methanol laser. It turns out that the focal length of the focussing mirror has to be adapted to the resonator perimeter. Eleven well suited focal length - resonator perimeter ratios, defining eleven standard resonator configurations, can be distinguished.The setup of an experimental laser with the optimized resonator and the experimental setup to measure laser performance are described, and results concerning laser output power, beam quality and efficiency are discussed.This paper is the extended version of the paper presented on the 23rd International Conference in Colchester [1] and continues a former article presented in this journal [2]. 相似文献
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Farzin Ghanadi Maziar Arjomandi Benjamin S. Cazzolato Anthony C. Zander 《Journal of Turbulence》2013,14(8):705-728
This study investigates the changes in the structure of a turbulent boundary layer downstream of a flow-excited Helmholtz resonator. To this end, a fully developed turbulent boundary layer over a resonator mounted flush with a flat plate was simulated by implementing a large eddy simulation (LES). To assist in understanding the effect of the resonator on the flow structure, a sensitivity study was undertaken by changing the main geometrical parameters of the resonator. The results demonstrated that when the boundary layer thickness equals the orifice length, the cross-stream component of velocity fluctuations penetrates the boundary layer, resulting in a reduction of the turbulence intensity by up to 12%. Therefore, it is concluded that a Helmholtz resonator has the potential to reduce the instabilities within the boundary layer. These investigations also assist in identifying the optimal parameters to delay turbulence events within the grazing flow using Helmholtz resonators. 相似文献
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Sung Soo Choi Dong Chul Park 《International Journal of Infrared and Millimeter Waves》2007,28(11):961-967
A new compact millimeter-wave dual-mode ring resonator bandpass filter is proposed. This filter has a 15% bandwidth at 58 GHz
with 3.4 dB insertion loss. Input/output lines and ring resonator are directly connected to obtain tight coupling, and an
open-end stub is inserted for dual-mode operation. This filter is fabricated on a GaAs wafer by using MEMS technology and
can be applied for the millimeter- wave SoC. 相似文献
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A novel colliding-enhanced Cr:LiSAF broad-band phase-conjugate resonator (PCR) has been investigated theoretically and experimentally. This kind of PCR is a low initiating threshold resonator. It can produce self-Q-switching narrow pulse with about 35 ns duration (FWHM), efficiently correct intracavity phase aberrations, and severalfold improve output laser beam quality. 相似文献
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Mao Hai-yan Wang Fu-ren Meng Shu-chao Mao Bo Li Zhuang-zhi Nie Rui-juan Liu Xin-yuan Dai Yuan-dong 《Frontiers of Physics in China》2006,1(3):301-304
A new type of HTc superconducting film combshape resonator for radio frequency superconducting quantum interference devices
(RF SQUID) has been designed. This new type of superconducting film comb-shape resonator is formed by a foursquare microstrip
line without a flux concentrator. The range of the center frequency of this type of resonator varies from 800 MHz to 1 300
MHz by changing the length of the teeth. In this paper, we report on simulating the relationship of the value of the center
frequency and the length of the teeth, and testing the noise of HTc RF SQUID coupling this comb-shape resonator.
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Translated from Chinese Journal of Low Temperature Physics, 2005, 27(3) (in Chinese) 相似文献
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WANG Tingyun * SUN Shenghe 《Chinese Journal of Lasers》1998,7(5):407-412
1IntroductionFiberopticringresonators(FORR)havebeeninvestigatedforanumberofyearsforfiberopticdelayelements[1],sensorapplica... 相似文献
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An improved TM110 resonator for continuous-wave and time-resolved electron-nuclear double resonance (ENDOR) studies at X-band frequencies is described that has been designed with small samples and/or light excitation in mind. The filling factor is increased by reducing the resonator length to only 16 mm. The radio-frequency field is generated by either a conventional solenoid for stable samples or by a pair of coils for samples which require photoexcitation. This arrangement leaves the central volume of the resonator free for optimal sample illumination, which is achieved through a slit in the wall of the resonator. Microwave coupling is achieved by the incorporation of an iris in the top of the resonator, and magnetic field modulation is applied by external coils. The resonator’s high sensitivity is illustrated by a study of the temperature dependence of the continuous-wave ENDOR signal of the stable neutral flavin radical in DNA photolyase and an investigation of the photoexcited triplet state of free-base tetraphenylbacteriochlorin by time-resolved ENDOR. 相似文献
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相位共轭谐振腔改善激光器波前像差特性研究 总被引:1,自引:0,他引:1
在高功率激光器中采用相位共轭谐振腔技术可以补偿动态波前像差,在校正畸变的输出光束方面有极其重要的应用。分析了相位共轭腔的模式结构特性及稳定性,在实际高功率激光器中采用相位共轭谐振腔,使得激光系统的光束质量得到了极大改善。通过实验数据分析,提出在激光器系统中描述光束质量只用PV值和RMS值来量度是不足的,并利用结合光束环围能量分布图像和平均离焦系数来评价系统光束质量。实验结果表明,采用相位共轭谐振腔使得焦平面环围能量更为集中,同时平均离焦系数更接近零,结合上述方法评价系统光束质量更具实际意义。 相似文献
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ANewResonatorWithANon─misalignedFourMirorReflectorAndItsEfectOnBeamQualityImprovementOfHighAveragePowerNd:YAGLasersC.M.Zhao,G... 相似文献
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提出了有关空心微瓶谐振腔的曲率变化模型并且研究了曲率对其传输特性的影响。仿真分析了微瓶谐振腔内回音壁模式的分布情况,随着曲率的增加,微瓶谐振腔对回音壁模式的束缚能力越强,使得内部光场能量也相应增加。通过控制熔接机的放电次数制得不同曲率的空心微瓶谐振腔,并且根据理想气体状态方程,推导了制备工艺中曲率模型,研究了空心微瓶谐振腔的曲率随放电次数的变化趋势。实验结果表明,曲率越大的空心微瓶谐振腔品质因子越高,可达到7.26×105,该结论在提升谐振腔的品质因子方面具有重要价值。 相似文献
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Optical waveguide ring resonator is the basic element of resonator integrated optic gyro (RIOG). In this paper, we report a novel configuration of optical waveguide ring resonator using a multi-turn structure. The characteristic of the light propagating across the crossed waveguides is analyzed using the finite difference beam propagation method. The relationship between the propagation loss and the intersection angle for arbitrary intersecting angles has been analyzed. Some crossed waveguides are fabricated in silica waveguides to verify the theoretical results. On this basis, the influences of the loop numbers and the excess loss of the crossed waveguide on the limited sensitivity of the RIOG have been analyzed. There is a critical intersection angle for certain resonator, only when the intersection angle is bigger than the critical angle, the gyro sensitivity can be improved by increasing the loop numbers. This will be helpful to how to determine the optimum length in resonator for its application in RIOG. 相似文献
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M.S. Howe 《Journal of sound and vibration》1976,45(3):427-440
This paper develops the theory of the excitation of a Helmholtz resonator by external disturbances located arbitrarily close to the mouth of the resonator. The classical approach of Rayleigh is thereby extended to situations in which the disturbance at the mouth is not necessarily equivalent to a uniform, time dependent pressure perturbation. The analysis involves the derivation of the Green function of the resonator in a manner similar to that described in an earlier paper. The use of the Green function is illustrated by two examples in which the resonator is excited by a low Mach number stream of air. In the first case the air stream has a periodic large scale structure such as may be caused by a Kelvin-Helmholtz type of instability. The second example models the case of excitation by a shear layer possessing a continuous spectrum of turbulent eddies. In both of these applications the orders of magnitude of the sound pressure levels involved are illustrated for a typical resonator. 相似文献
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A. A. Vertiy S. P. Gavrilov D. S. Armaan I. ?l?er 《International Journal of Infrared and Millimeter Waves》1997,18(2):405-429
In the present paper a time response of a quasi-optical open resonator when exciting it by a pulse signal with a radiofrequency
filling has been investigated using an inverse Fourier transformation. The radiofrequency filling corresponds to millimeter
wavelengths region. Fourier image of the time response of the resonator is calculated from a product of two frequency’s functions.
One of these functions is the Fourier image of a pulse signal at the resonator input, and the second is a calculated or measured
amplitude — phase characteristic of the resonator. When calculating the amplitude- phase characteristic of the resonator (a
complex transfer coefficient) a plane — layered model of the resonator was used.
Experimental investigation has been conducted in millimeter wavelengths with Fabry-Perot type open resonator. Amplitude- phase
characteristic of the resonator were measured in “on passage“ regime in wide frequency band.
It was shown that presence of weakly absorbing layer in the resonator leads to changing of the time response of the resonator.
The obtained results can be used in the dielectric measurements, defectoscopy of stratiform materials, relaxometry, non-destructive
control of materials and structures, etc. 相似文献