Exploration of Higher-Order Mode Coupling in Long-Period Gratings for Sensitive Monitoring of Polyelectrolyte Self-Assembly at Nanoscale

0436244 - ÚFE 2015 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Tian, F. - Kaňka, Jiří - Li, X. - Du, H.
Exploration of Higher-Order Mode Coupling in Long-Period Gratings for Sensitive Monitoring of Polyelectrolyte Self-Assembly at Nanoscale.
Fiber Optic Sensors and Applications XI. Vol. 9098. Bellingham: SPIE, 2014 - (Du, H.; Pickrell, G.; Udd, E.), 90980R1-90980R8. ISBN 9781628410358. ISSN 0277-786X.
[Fiber Optic Sensors and Applications XI. Baltimore (US), 08.05.2014-09.05.2014]
Grant CEP: GA MŠMT(CZ) LH11038
Institucionální podpora: RVO:67985882
Klíčová slova: Long-period grating * single mode fiber * mode coupling
Kód oboru RIV: JA - Elektronika a optoelektronika, elektrotechnika

Layer-by-layer (LbL) self-assembly via hydrogen bonding is one of the primary mechanisms to achieve stimuliresponsive polyelectrolyte thin films for a variety of applications. The ability to monitor the individual LbL steps in situ is of great significance in the development and understanding of hydrogen-bonded LbL systems of new design functions and properties. Long-period gratings in single-mode fiber (SMF-LPG) has the potential for such application by virtue of its high index sensitivity. We report a theoretical and experimental investigation to sort out the coupled cladding mode that is most sensitive to molecular adsorption events during LbL deposition. We have undertaken a combined theoretical and experimental investigation to illustrate and demonstrate the strong correlation between the order of the coupled cladding modes in long-period gratings (LPG) in conventional single mode fiber and their sensitivity to the process of layer-by-layer (LbL) assembly of polyelectrolyte multi-layers. We show that high-order cladding modes such as LP0,10 in LPG are significantly more sensitive than their lower-order counterparts such as LP0,2, with LP0,10 yielding a shift of 1.575 nm in resonance wavelength per polyelectrolyte repeating unit of poly(vinyl pyrrolidone)/poly(methacrylic acid) bi-layer. We illustrate the potential utility of SMF-LPG integrated with stimuli-responsive LbL thin films as sensors. The integrated LPG/LbL strategy as a robust LbL test-bed has broad ramifications in exploring and exploiting sensors and devices enabled by versatile, stimuli-responsive polyelectrolyte thin films
Trvalý link: http://hdl.handle.net/11104/0240020