We present a simple modification of the tube etching process for the fabrication of fiber probes for near-field optical microscopy. It increases the taper angle of the probe by a factor of two. The novelty is that the fiber is immersed in hydrofluoric acid and chemically etched in an upside-down geometry. The tip formation occurs inside the micrometer tube cavity formed by the polymeric jacket. By applying this approach, called reverse tube etching, to multimode fibers with 200/250 mu m core/cladding diameter, we have fabricated tapered regions featuring high surface smoothness and average cone angles of similar to 30 degrees. A simple model based on the crucial role of the gravity in removing the etching products, explains the tip formation process. (c) 2006 Elsevier B.V. All rights reserved.
Wide angle near-field optical probes by reverse tube etching RID F-3894-2011
ALLEGRINI, MARIA
2006-01-01
Abstract
We present a simple modification of the tube etching process for the fabrication of fiber probes for near-field optical microscopy. It increases the taper angle of the probe by a factor of two. The novelty is that the fiber is immersed in hydrofluoric acid and chemically etched in an upside-down geometry. The tip formation occurs inside the micrometer tube cavity formed by the polymeric jacket. By applying this approach, called reverse tube etching, to multimode fibers with 200/250 mu m core/cladding diameter, we have fabricated tapered regions featuring high surface smoothness and average cone angles of similar to 30 degrees. A simple model based on the crucial role of the gravity in removing the etching products, explains the tip formation process. (c) 2006 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
