Study On The Realization Of Micro/nano Sensor Structure Based On PDMS Transfer Method On Fiber End Facets

Micro/nanostructured fiber sensors combine nanofabrication technology with optical fiber sensing technology and have great scientific research significance and industrial potential.The existing fabrication methods cannot produce arbitrary three-dimensional structures at the fiber end facet,which limits the development of the micro/nanostructured fiber sensors.This paper puts forward a new fabrication method for microstructured fiber sensors by transferring micro/nanostructures onto fiber facets.This method fabricates nanostructure on top of polydimethylsiloxane(PDMS)thin films utilizing mature fabrication technology,then transfers the microstructure together with the PDMS film to fiber facets.This paper verified the viability of this method by combined simulational and experimental work.First,the microstructures are designed based on the theoretical knowledge of localized surface plasmon resonance.Using thefinite difference time domain method as the theoretical foundation,the structures are optimized by FDTD-solutions software.Then,the microstructures are fabricated on top of the PDMS thin films by the interference photolithography technology.After that,the PDMS thin films are transferred onto the fiber facet to realized arbitrary three-dimensional structures on fiber facet.Finally,the samples were checked using a scanning electron microscope to verify that the PDMS films and the structures can be transferred without damage.The optical properties of the prepared samples were tested and analyzed.The extintion spectra of the sensing fibers were measured in aqueous glucose solutions with different concentrations,and different refractive indexes were detected by the optical fiber sensor.The results showed that the extinction spectra redshifted with the increase of the refractive index of glucose solution,which was consistent with the simulation results.Experimental results show that the fabrication method proposed by this work is easy to use,cost-efficient,and can produce three-dimensional structures.