Proceedings Article | 7 April 2008
Proc. SPIE. 6933, Smart Sensor Phenomena, Technology, Networks, and Systems 2008
KEYWORDS: Refractive index, Photonic crystal fibers, Polarization, Sensors, Ions, Carbon dioxide lasers, Single mode fibers, Telecommunications, Biological and chemical sensing, Temperature metrology
We present a simple, low-cost, temperature- and strain-insensitive long-period gratings (LPGs) written in photonic
crystal fibers (PCFs) that can be used as sensitive chemical solution sensors or bend sensors for a variety of industrial
applications, including civil engineering, aircraft, chemistry, food industry, and biosensing. Three different
configurations of PCFs have been used for this study, including a polarization maintaining PCF, a large mode area PCF
and an endlessly single mode PCF. These LPGs have been characterized for their sensitivity to temperature, strain,
bending, and surrounding refractive index. Transmission spectra of the LPGs were found to exhibit negligible
temperature and strain sensitivities, whereas possessing usable sensitivity to refractive index and bending. This type of
PCF sensor could in principle be designed for optimum sensitivity to desired measurand(s), while minimizing or
removing undesirable cross-sensitivities. The unique sensing features of PCFs are particularly suited for a wide variety
of applications in smart structures, embedded materials, telecommunications and sensor systems.
