Microstructured Optical Fibers Filled with Carbon Nanotubes: Photonic Bandgap Modification and Sensing Applications

Abstract

In the recent years, a new concept is emerging in the scientific community dealing with the possibility to use optical fibers as platform to develop all-in-fiber multimaterial and multifunctional optical devices and systems (Abouraddy et al., 2007). The key feature of these new optoelectronic devices relies on the proper integration of specific materials, such as conductors, semiconductor and insulator, into the same optical fiber in order to attain advanced functionalities within a single optical fiber. A promising building block to realize these multifunctional optoelectronic devices are the Microstructured Optical Fibers (MOFs) which, being composed by a periodic distribution of micrometric air-holes running uniformly along the fiber length (Knight et al., 2003), offer an high degree of freedom in their fabrication and at the same time several opportunities of integration with specific materials. Also by manipulating the properties of the in-fiber integrated materials, the guiding features of the MOF itself can be properly changed in order to develop new tunable photonic devices (Domachuk et al. 2004; Larsen et al. 2003; Huang et al. 2004) as well as optical fiber sensors (Benabid et al. 2005; Matejec et al. 2006). Single Walled Carbon Nanotubes (SWCNTs) constitute a very promising material for multimaterial and multifunctional photonic devices in light of their unique electrical and mechanical properties (Dresselhaus et al. 2001). Furthermore, the opto-chemical sensing properties of carbon nanotubes, deposited onto singlemode standard optical fiber (SOF) configured in buffered and not buffered reflectometric configurations, have been demonstrated to be suitable (Penza et al. 2004; Penza et al. 2005 ; Consales et al. 2006; Consales et al. 2007) to perform chemical detection of volatile organic compounds (VOCs) at room temperature. 26