Manipulating The Fluorescence Emission With New Type Of Optical Chips

Fluorescence-based techniques have been widely used in bioscience,chemical analysis and other fields.How to improve the detection efficiency and detection sensitivity is the addressing issues of people's concern.In recent years,with the development of micro-nano fabrication technology,new type of optical chips based on micro-nano composite structures were more and more used in fluorescence radiation field modulation.In this paper,we propose several optical chips to modulate the optical field by analyzing the modes in the micro-nano composite structures and the coupling of excited fluorescence with eigen-mode fields.We designed a back focal plane imaging system to characterize the optical behavior of radiation field.These optical chips are so compact that contribute to the miniaturization and integration of devices,and have broad prospects for fluorescence micro-imaging,drug tests,sensory analysis and many other areas.The main research works and conclusions are following:1.Building a back focal plane imaging system.We use back focal plane to describe the radiant angle,intensity,polarization of radiation field,analyze the relation of relative position of one point in the back focal plane and corresponding angle.Analyzing the variation of the angle can obtain the change of the wave vector,which can be used in refractive measurement of liquids and thin film.2.Designing optical chips based on dielectric gratings to extracting the surface wave coupled emission field in free space.The coupling of excited fluorescence and surface wave can realize the directional emission of fluorescence,improve the detection sensitivity.Then use substructure dielectric gratings for further modulation.3.Proposing hybrid aperture-Tamm structure.We use transfer matrix method analyzing electromagnetic field how to transmit and resonance modes in this structure.Simulate the far field information with finite-different time-domain.Demonstrate emission angle and intensity can be modulated by emission wavelength,position of dipole source and the size of apertures.Highlights of the dissertation are as following:1.The building back focal plane imaging system contains excitation light source,lens system and filters.We can choose laser or white beam as excitation light,select the proper wavelength,and imaging front focal plane and back focal plane at same time.And obtain the angle an intensity information directionally.The whole system has high flexibility and practicability.2.Proposing subwavelength dielectric gratings to extracting suface wave coupled emission in free space.We fabricate gratings in two dimensions to modulate optical field in different directions.This new structure improve the fluorescence detection efficiency,sensitivity and signal to noise ratio.3.Hybrid aperture-Tamm structure combined surface shape with Tamm structure.This structure can realize fluorescence vertical emission and also help the dipole source located in the nano-aperture interact better with Tamm Plasmon Polariton.Compared with conventional Tamm structure,emission intensity two orders of magnitude.