DETECTION OF MAGNETO-OPTIC EFFECT OF THE VACUUM-HIGH-SENSITIVITY POLARIZATION SPECTROSCOPY

我们研究了高灵敏度偏振光谱来检测真空的磁光效应。1)用来检测真空中诱导的超小双折射。利用光腔来增强偏振信号。我们提出了一种偏振检测系统，在该系统中，单个腔体具有两种功能：信号增强和锁定激光频率。利用该系统和低精细度腔，我们获得了法拉第效应测量的‘32信号增强。同时，我们构造了一个高精细腔(F=6×10^4)，并用偏振相关腔衰荡方法研究了腔镜的光学各向异性。我们提出了通过优化反射镜的光轴来最小化各向异性。2)我们发展了单程排列的高灵敏度偏振信号检测。为了降低背景噪声，我们将偏振分析仪系统的消光比提高到10^~(-10)~(-10)，使光源强度起伏引起的噪声降到了散粒噪声以下。可以检测到的椭圆度变化的最小值为10^&lt；-10；rad。我们可以探测到磁感应双折射最小的He气体的非共振Voigt效应。本研究的结果对开发检测真空磁光效应的偏振光谱系统是有用的

We investigated high-sensitivity polarization spectroscopy for detection of the magneto-optic effect of the vacuum.1) For detection of the ultra-small birefringence induced in the vacuum. Optical cavities are used to enhance the polarization signal. We proposed a polarization detection system in which a single cavity served two functions : signal enhancement and locking of a laser frequency. Using this system with a low finesse cavity we obtained the ' signal enhancement of 32 for the Faraday effect measurement. Meanwhile, we constructed a high-finesse cavity (F= 6 x 10^4 ), and investigated the optical anisotroy of the cavity mirrors using the polarization dependence cavity ring down method. We presented to minimize the anisotropy by optimization of the optical axes of the mirrors.2) We developed the high-sensitivity detection of the polarization signal for a single-pass arrangement. In order to reduce background noise we improved the extinction ratio of the polarization analyzer system to 10^<-10> so that the noise caused by intensity fluctuation of the light source was reduced to a level below that of shot noise. The minimum value that could be detected for the ellipticity change was 10^<-10> rad. We could detect the off-resonant Voigt effect of He gas that had the smallest value of the magnetically induced birefringence.The results thus obtained in the present study are useful for development of the polarization spectroscopic system to detect the magneto-optic effect of the vacuum