Fabrication and characterization of fluorescent rare-earth-doped glass-particle-based tips for near-field optical imaging applications.
Fluorescent rare-earth-doped glass particles glued to the end of an atomic force microscope tip have been used to perform scanning near-field optical measurements on nanostructured samples. The fixation procedure of the fluorescent fragment at the end of the tip is described in detail. The procedure consists of depositing a thin adhesive layer on the tip. Then a tip approach is performed on a fragment that remains stuck near the tip extremity. To displace the particle and position it at the very end of the tip, a nanomanipulation is achieved by use of a second tip mounted on piezoelectric scanners. Afterward, the particle size is reduced by focused ion beam milling. These particles exhibit a strong green luminescence where excited in the near infrared by an upconversion mechanism. Images obtained near a metallic edge show a lateral resolution in the 180-200-nm range. Images we obtained by measuring the light scattered by 250-nm holes show a resolution well below 100 nm. This phenomenon can be explained by a local excitation of the particle and by the nonlinear nature of the excitation.
Aigouy
Lionel
L
Laboratoire Spectroscopie en Lumière Polarisee, Unite Propre de Recherche (UPR A0005), Centre National de la Recherche Scien- tifique, Ecole Superieure de Physique et de Chimie Industrielles, 10 rue Vauquelin, 75231 Paris, France. aigouy@optique.espci.fr
De Wilde
Yannick
Y
Mortier
Michel
M
Giérak
Jacques
J
Bourhis
Eric
E