Magnetic field measuring apparatus capable of measuring at high spatial resolution

Abstract

A condenser lens is incorporated into the end portion of a magnetic field measuring apparatus including a magneto-optical crystal. Alternatively, the end portion of the magnetic field measuring device includes an optical fiber having a core diameter smaller than that of a normal single-mode optical fiber.

1 . A magnetic field measuring apparatus comprising:
 a magneto-optical crystal as a magnetic field detecting element;   a measuring system comprised of a plurality optical devices; and   an optical fiber connecting between the magneto-optical crystal and the measuring system;   wherein the optical fiber has a core diameter smaller than that of a single-mode optical fiber.   
   
   
       2 . The magnetic field measuring apparatus according to  claim 1 , wherein the optical fiber having the core diameter smaller than that of the single-mode optical fiber is a high-numerical-aperture fiber or a photonic crystal fiber.