title: Photonic crystal fiber long-period gratings for biochemical sensing.
abstract: We present experimental results showing that long-period gratings in photonic crystal fibers can be used as sensitive biochemical sensors. A layer of biomolecules was immobilized on the sides of the holes of the photonic crystal fiber and by observing the shift in the resonant wavelength of a long-period grating it was possible to measure the thickness of the layer. The long-period gratings were inscribed in a large-mode area silica photonic crystal fiber with a CO2 laser. The thicknesses of a monolayer of poly-L-lysine and double-stranded DNA was measured using the device. We find that the grating has a sensitivity of approximately 1.4nm/1nm in terms of the shift in resonance wavelength in nm per nm thickness of biomolecule layer.
authors.forename: Lars
authors.initials: L
authors.lastname: Rindorf
authors.forename: Jesper B
authors.initials: JB
authors.lastname: Jensen
authors.forename: Martin
authors.initials: M
authors.lastname: Dufva
authors.forename: Lars Hagsholm
authors.initials: LH
authors.lastname: Pedersen
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Høiby
authors.forename: Ole
authors.initials: O
authors.lastname: Bang