Magnetooptical thin film reading head

Detection of magnetic data using a magnetooptic indicator

“…Such detailed calculations require extensive computational efforts, and will not be considered here. Instead we will follow Hatakeyama et al [4], who assumed that the field from a source of size b has a z-component given by…”

“…Many attempts have been directed towards reading out magnetic data by optical systems, since optical readout systems have many interesting features not possessed by magnetic readout heads [2][3][4][5]. However, in most optical systems the resolution is limited by the classical diffraction limit ∼ λ/2NA, where λ is the wavelength of light, and NA is the numerical aperture.…”

“…However, in most optical systems the resolution is limited by the classical diffraction limit ∼ λ/2NA, where λ is the wavelength of light, and NA is the numerical aperture. A possible way to circumvent this problem was introduced by japanese researchers in the 1980's [4,5]. In 1986, Hatakeyama et al [4] reported that when a thin magnetic film is positioned normally to the recording medium surface, i.e., similar to a single-pole magnetoresistive head, a higher linear resolution may be expected.…”

“…A possible way to circumvent this problem was introduced by japanese researchers in the 1980's [4,5]. In 1986, Hatakeyama et al [4] reported that when a thin magnetic film is positioned normally to the recording medium surface, i.e., similar to a single-pole magnetoresistive head, a higher linear resolution may be expected. To demonstrate the principle, they sputtered a Co-Zr thin film on glass, and added a nonmagnetic mirror.…”