Stepwise fabrication of arbitrary fiber optic tapers
Citation
Felipe, A., Espı́ndola, G., Kalinowski, H. J., Lima, J. A. S., & Paterno, A. S. (2012). Stepwise fabrication of arbitrary fiber optic tapers. Optics Express, 20(18), 19893–19904. This article was received on April 26, 2012 and accepted on July 6, 2012. The authors acknowledge financial support from the National Council for Scientific and Technological Development (CNPq) under grant number 308975/2009-0.
Keywords
- Fiber optic tapers
- Flame-brush technique
- Arbitrary waist profiles
- Step-tapers
- Taper transition regions
- Fiber couplers
- Biconical tapers
- Nanotapers
- Optical fiber nanowires
- Near-field optical probes
- Fiber optic sensing
- Soliton propagation
- Supercontinuum generation
- Viscous fluid flow model
- Distance law
- Volume law
Brief
A modified flame-brush technique fabricates fiber optic tapers with arbitrary waist profiles by approximating the taper diameter function to any monotonic function of the fiber length while combining a superposition of step-tapers.
Summary
A modified flame-brush technique was used to fabricate fiber optic tapers with arbitrary waist profiles. The technique uses a flame brush to create small, step-like reductions in fiber diameter.1 By combining multiple step-tapers, arbitrary waist profiles can be created. This method was used to create tapers with several different transition regions. The researchers used a taper rig with two translation stages to stretch the fiber and a flame-brush controlled by digital mass-flow controllers. The flame brush, fueled by butane and oxygen, was 3mm wide.
The researchers used a simplified fluid-dynamic model to simulate the tapering process and determine the proper speeds for the translation stages and flame-brush. The model considers the conservation of mass and momentum, and the viscosity of the fiber as a function of length. The researchers also developed a mathematical model to describe the tapering process. This model uses a volume law, based on the principle of conservation of volume, and a distance law, which relates the distances associated with the transition lengths. The researchers found that the stepwise method could accurately produce arbitrary taper profiles. They also observed a correspondence between the movement of the flame-brush and the resulting taper profile. The researchers concluded that this technique could be used to create tapers with complex shapes.