MAGNETIC FIELD TRANSDUCER Russian patent published in 2000 - IPC

FIELD: magnetic measurement technology. SUBSTANCE: magnetic field transducer is used for defectoscopy of ferromagnetic articles. It has light source, device for delivery of radiation into optical fiber, optical fiber with magnetic film positioned in its intermediate part, and photodetector installed at fiber output. Transducer also includes light beam widener positioned between input optical fiber and magnetooptical material. Input optical fiber is made supermode, and output optical fiber is made multimode containing no light absorbing layer in center of light-guiding core. Thickness of light absorbing layer is connected with numerical aperture of output optical fiber by relation , where λ - is light wave length; h is thickness of light absorbing layer; NA is numerical aperture of optical fiber. EFFECT: enhanced accuracy of measurement. 2 cl, 1 dwg