Murakami Hironaru, Tonouchi Masayoshi
Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
Rev Sci Instrum. 2010 Jan;81(1):013701. doi: 10.1063/1.3276710.
A high-sensitive scanning laser magneto-optical (MO) imaging system has been developed. The system is mainly composed of a laser source, galvano meters, and a high-sensitive differential optical-detector. Preliminary evaluation of system performance by using a Faraday indicator with a Faraday rotation coefficient of 3.47 x 10(-5) rad/microm Oe shows a magnetic sensitivity of about 5 microT, without any need for accumulation or averaging processing. Using the developed MO system we have succeeded in the fast and quantitative imaging of a rotationally symmetric magnetic field distribution around an YBa(2)Cu(3)O(7-delta) (YBCO) strip line applied with dc-biased current, and also succeeded in the detection of quantized fine signals corresponding to magnetic flux quantum generation in a superconducting loop of an YBCO Josephson vortex flow transistor. Thus, the developed system enables us not only to do fast imaging and local signal detection but also to directly evaluate both the strength and direction of a magnetic signal.
已开发出一种高灵敏度扫描激光磁光（MO）成像系统。该系统主要由激光源、检流计和高灵敏度差分光探测器组成。通过使用法拉第旋转系数为3.47×10（-5）rad/μm Oe的法拉第指示器对系统性能进行初步评估，结果显示磁灵敏度约为5μT，无需任何累积或平均处理。利用所开发的MO系统，我们成功地对施加直流偏置电流的YBa（2）Cu（3）O（7-δ）（YBCO）带状线周围的旋转对称磁场分布进行了快速定量成像，并且还成功地检测到了与YBCO约瑟夫森涡旋流晶体管超导回路中磁通量量子产生相对应的量化精细信号。因此，所开发的系统不仅使我们能够进行快速成像和局部信号检测，而且能够直接评估磁信号的强度和方向。
