Reflection-mode scattering-type scanning near-field optical microscope using a laser trapped gold colloidal particle as a scattering probe

We have developed a reflection-mode scattering-type scanning near-field opt ical microscope using a laser trapped gold colloidal particle as a scatteri ng probe and succeeded in observing the reflectance change of an opaque sem iconductor sample with the alternating layers of GaAs and Al0.55Ga0.45As. T he spatial resolution became as high as 200 nm when using a 200 nm gold col loidal particle. The results indicated that the resolution obtained in the experiment is in good agreement with the trapped particle size and overcame the diffraction limit (420 nm) of the lens system. (C) 2001 American Insti tute of Physics.