Microfabricated Fiber Probe by Combination of Electric Arc Discharge and Chemical Etching Techniques

In this study, optical fiber probes were fabricated by combination of electric arc discharge and chemical etching techniques. Size of tips diameters fabricated using different etching solutions were observed. When the optical fibers were pulled and heated by the electric arc discharge using a fusion splicer, fiber tips with few microns in diameter were obtained. To minimize the tips diameter, the pulled fiber probes were etched vertically for 10 minutes using two different etching solutions namely 49% HF and HF buffer solution (49% HF and 40% NH4F) with ratio of 2:1. A thick overlayer was added on top of the HF solution to prevent dangerous vapors escape to the environment. When the tapered part of the pulled fiber (FP1) was dipped into 49% HF solution, the diameter of tip was slightly decreased from 4.41μm to 1.31μm with etching rate of 5.17x10-3 μms-1. When the pulled fiber (FP2) was etched into HF buffer solution, the etching rate was increased up to 52.35% with the etching rate of 10.85x10-3μms-1. The tip diameter was reduced from 7.01μm to 468.9 nm in diameter. Combination of “heat and pull” technique with chemical etching by using HF buffer solution produced fiber probe with small tip diameter.