Observations of magneto-optic phase contrast using a scanning laser microscope

Abstract

A scanning laser microscope (SLM) has been built which is capable of observing magnetic structure via ‘‘conventional’’ Kerr imaging techniques and a ‘‘novel’’ magneto-optic phase contrast approach. This latter contrast mode highlights magnetic transitions, rather than domains themselves. In this paper we present results of observations in TbFeCo samples using this phase contrast technique and assess its possible application as a read-out mechanism for magneto-optic recording systems.

Scanning Laser Microscopy for Evaluation and Characterisation of Magneto-Optic Recording Materials and Systems

“…Since in this paper we are concerned mainly with magneto-optic stomge media with perpendicular anisotropy, we make no more reference to the longitudinal effect, but the interested reader is referred to earlier works [1,2,3]. Magneto-optic phase contrast (MOPC) or the so-called edge detection technique, which relies on light diffracted by magnetisation transitions rather than polarisation rotation caused by the domains themsleves, provides an alternative contrast mechanism for perpendiculary magnetised films [4,5,6]. This contrast can also be generated easily in our SLM by two methods.…”

“…We have previously reported on the use of the SLM for conventional laser beam modulation read/write studies of TbFeCo and PtCo multilayer films [11], for magnetic field modulation studies on TbFeCo films [12] and for assessment of the edge detection readout technique [6,13]. Some of the interesting read/write testing capabilities are illustrated by Fig.…”

Scanning heterodyne Kerr-effect microscope for imaging of magnetic tracks

“…Some of them use wide illumination in traditional microscope imaging schemes with television cameras as image detectors [1][2][3][4][5] while the others implement singlechannel photodetectors and focused light beams coupled with various types of scanning techniques to render images. [6][7][8][9][10][11][12][13][14] In recent years various combinations of these two approaches have become popular ͑Ref. 15, and references herein͒.…”

The DESIGN OF a COMBINED OPTICAL DISC TESTER AND R-Θ SCANNING LASER MICROSCOPE

“…In the current work we describe a novel SLM based instrument which combines the ability to record and replay magneto-optic domains at high headmedia speeds, together with the ability to image the recorded area with sub-micron resolution using a variety of contrast mechanisms. Available contrast modes include conventional non-magnetk contrast, polar Kerr contrast and magneto-optic phase contrast or edge detection [2,3] techniques. The system is also able to perform a wide range of standard recording te:sts on disk samples, including carrier to noise ratio measurements, pulse width determination and jitter characterisation.…”