Study Of Fiber-Optical Nanoprobes By Chemical Etching And Chemical Coating

Fiber-optical nanoprobes are the key elements for detecting and analyzing micro-scale objects in near-field optical microscopes and fiber-optical nano-biosensors. Fabrication of nanoprobes is very important to their performances, so it is significance to develop a good and simple fabrication technique.The fiber-optical nanoprobes are firstly fabricated by the chemical etching in hydrofluoric acid. The fiber tips with the diameters less than 100 nm and smooth surfaces are obtained. The influence of etching time and etchant concentration on the probe quality is studied. The nano fiber tips are then coated with silver by chemical coating in order to screen the light. The apertures are formed at the top of the probes due to the surface tension. We have discussed the influence of coating solution's concentration on the quality of films, and the influence of coating time on the thickness of films. To improve the quality of films, we apply the ultrasonic into the coating process. It shows that the films are tighter and more adhesive to the probe surfaces, and tend to be smoother with less pinholes.From the experiment results we can prove that, it is feasible to coat fiber-optical nanoprobes with silver by chemical coating, and applying the ultrasonic can highly improve the quality of films.