MEASURING DEVICE OF MAGNETIC FIELD

摘要

PURPOSE:To obtain a small-sized and reliable device having high sensitivity and a wide measuring range by using two magnetooptical elements consisting of a ferromagnetic garnet crystal and a paramagnetic magnetooptical element or a diamagnetic magnetooptical element. CONSTITUTION:Light from a light source 6 is made incident to a SELFOC lens 4a through an optical fiber 5a and separated into two straight polarized light rays by a polarizer 2. These light rays have fine temperature characteristics and are made incident to the ferromagnetic garnet crystal 1a of which both the sides are ground as parallel mirror surfaces and the diamagnetic magnetooptical element 1b of which both the sides are grfound as parallel mirror surfaces respectively. Analyzers 3a, 3b are arranged so that transmitted polarized light directions are inclined by 45 deg. respectively from respective straight polarized wave directions polarized and separated by the polarizer 2. The optical output transmitted through the magnetooptical conversion part is converted into an electric signal corresponding to the light intensity by detecting means 7a, 7b through SELFOC lenses 4b, 4c and fibers 5b, 5c and Ii and I2 are outputted as measured values in case of a low magnetic field and a high magnetic field respectively.