POLARIZATION PROPERTIES OF LIGHT EMITTED BY A BENT OPTICAL-FIBER PROBE AND POLARIZATION CONTRAST IN SCANNING NEAR-FIELD OPTICAL MICROSCOPY

This article describes the polarization properties of light emitted by a bent optical fiber probe which is used for scanning near-field opti cal microscopy operated in atomic force mode (SNOM/AFM). SNOM/AFM can be applied to the observation of magnetic domains by imaging polarizat ion contrast in transmission mode. A bent optical fiber probe with a s ubwavelength aperture is vibrated vertically as a cantilever for atomi c force microscopy. Plane polarized Light with an extinction ratio of better than 70:1 was emitted by the aperture by controlling the polari zation state of incident light to the probe. A particular transverse p olarization component of light transmitting a sample is selected by a polarization analyzer and detected. We obtained clear polarization con trast images of 0.7 mu m length bits written with a conventional metho d using a focused laser beam on a bismuth-substituted dysprosium-iron- garnet film. (C) 1998 American Institute of Physics.