On classification of eigenmodes of an open resonator with spherical mirrors

A rigorous mathematical model describing eigenmodes of open resonators with spherical mirrors is proposed. Theoretical analysis of the spectral characteristics of an open resonator is performed for the case where the wavelength is comparable with the resonator size. Specification and significant generalization of eigenmode classification based on approximate open-resonator models are proposed. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 12, pp. 1051–1060, December 2008.     

Axisymmetric eigenmodes of magnetic type in an open resonator with spherical mirrors

We develop a rigorous mathematical model describing axisymmetric eigenmodes of magnetic type of open resonators with spherical mirrors. On the assumption that the spectrum of complex eigenfrequencies of an open resonator exists, it is proved that this spectrum is discrete and has finite multiplicity with a single accumulation point at infinity. Theoretical analysis of the spectral characteristics of an open resonator is performed in the case where the wavelength is comparable with the resonator sizes. The limits of applicability of the well-known asymptotic models of open resonators are established. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 9, pp. 787–798, September 2006.     

Determination of the losses in a ruby laser with a misaligned resonator

A technique for the determination of the losses in a ruby laser with a misaligned resonator is presented. It is shown that a probabilistic formula for the power generation correctly describes the relation between the generated power and the angle between the resonator mirrors if the experimentally determined loss figures are inserted into this formula.     

Low power measurements of the quality factor of an open resonator with stepped mirrors

Open resonators in which both mirrors have a central step have been predicted to exhibit mode selection properties. This is advantageous for the design of quasi-optical gyrotrons. Quality factor measurements of a 36 cm resonator at 120 GHz are presented and compared with theory. Although the effect of the step is clearly seen, the quality factor Q of the resonator is lower than that predicted.     

球共振声学法测量普适气体常数

设计和建立了高精度的球共振声学法气体音速测量装置,分析了实际的球共鸣器的结构对共振频率的影响,并给予了相应的修正.测量了温度为29315K,压力在02MPa—08MPa范围内氩气的音速,并根据音速数据确定了普适气体常数.实验温度、压力和普适气体常数的不确定度分别为±14mK,±2kPa和±00036%.最终确定的普适气体常数R为831439±000030J·mol-1·K-1. 关键词： 普适气体常数 音速 球共振器 声学法     

Open resonator modes with an optically inhomogeneous region between the mirrors

Using Huygens' principle, which is correct for an optically inhomogeneous medium in the quasi-geometrical approximation, for the two-dimensional case an integral equation has been obtained for the modes which occur on the mirrors of a symmetric resonator with an optically inhomogeneous region between them. This integral equation has been solved in analytic form for the case of small modes, whose field is concentrated in the inner mirror region. The conditions which the resonator parameters and the inhornogeneous region must satisfy in order to obtain small modes and correspondingly small diffraction losses in the resonance system as a whole are considered. The number of small modes has been estimated for the system.In conclusion I wish tiespress my gratitude to Prof. V. A. Fabrikant for his interest in this work, for frequent discussions and valuable advice.     

激光辐照下非稳腔镜变形对激光模式的影响

分析了正支虚共焦非稳腔中腔镜变形对激光模式的影响,采用时间离散化、快速傅里叶变换（FFT）和有限元分析(FEA)方法解决腔镜变形和激光模式两者之间的耦合问题。计算结果表明,随着激光器工作时间的增加,腔镜温升和变形相应增大,谐振腔模式变差,输出光场相位均匀性变差,呈现散焦现象,输出光束质量下降。实验验证了激光器输出光束质量随出光时间的延长而逐渐变坏。