VOLTAGE MEASURING PROBE

摘要

PROBLEM TO BE SOLVED: To provide a voltage measuring probe in which a probe can be replaced easily and by which a voltage can be measured with high accuracy by a method wherein a magnet is fixed to the surface of an electro-optical element and the probe is attracted and fixed, so as to be replaceable, to the rear surface of the electro-optical element due to the magnetic force of the magnet. SOLUTION: A probe 13 is attracted and fixed to the rear surface of an electro-optical element 11 due to an attractive force acting across a magnet 12 and a magnetic body 14. When the magnet 12 is magnetized in the up-and-down direction, the probe 13 can be attracted strongly to the rear surface of the element 11. A conductor needle 15 is knocked on an interconnection to be measured, and the electric signal of the interconnection to be measured is applied to the element 11 via the conductor needle 15. In addition, laser light 16 is incident on the element 11 from the side of the element 11, and the polarization state of laser light 17 radiated from the element 11 is detected. Thereby, the voltage of the electric signal of the interconnection to be measured can be measured. The electric signal of the interconnection to be measured is applied to the element 11 via only the conductor needle 15, and the transmission line up to the element 11 from the interconnection, to be measured, of the electric signal is made short. As a result, the transmission property of the electric signal is made good, and the voltage of the electric signal can be measured at high speed and with high accuracy.