Angle-resolved Spectral Measuring System Based On Back Focal Plane Imaging And Its Key Technology

Surface Plasmons(SPs)is generally referred to the resonant oscillations of free electrons in metal nanostructures.By virtue of its unique optical properties,SPs has been applied in lots of fields like surface enhanced Raman scattering(SERS),surface enhanced fluorescence,biochemical sensing with high sensitivity,sub-wavelength optical waveguide and so on.The study on SPs' characteristics and applications requires the controllable excitation and collection of SPs,and SPs' excitation has directional properties.Therefore,angle-resolved spectral measuring system is an important and effective method to study the properties of SPs.Based on the target and requirement of the National Natural Science Foundation Project "The establishment of angle-resolved spectral measuring system and its application in the optical representation on controllable directional SERS substrates",the design and construction about the angle-resolved spectral measuring system based on back focal plane imaging is discussed and the experimental application is explored in this thesis to study the angular optical properties of the plasmonic samples.The main work of this thesis includes:1.The optical path structure of the angle-resolved spectral measuring system is designed,which includes the excitation path and the collecting path.The parameters of the optical components and the influence of every optical components in this optical path are analyzed.The optical path structure is simulated by Zemax to verify the effectiveness of the optical scheme.2.Based on the optical cage system,the optical mechanical structure of the angle-resolved spectral measuring system is designed,the complete optical path is constructed and the complete optical path debugging process is also designed to ensure the openness and stability of the whole optical structure.The key parameters such as the relationship between pixel in the back focal plane image and collecting angle,the resolution of the excitation angle and collecting angle are calibrated.3.The functional requirement of the measuring system is analyzed and the software of the angle-resolved spectral measuring system is realized by C#language completely,which mainly includes motion control and spectral data acquisition module,spectrum and image processing algorithm module and user interface.4.Dependability of the angle-resolved spectral measuring system is verified by experiments and some related applications are explored.The back focal plane images of gold film are acquired to verify the angular resolution and the angle-resolved reflective spectrum of the one-dimensional periodic grating is acquired and contrast the theoretical calculation result to verify the dependability.The two-dimensional periodic nanostructure sample is characterized by the angular reflective spectrum,and then the angle-resolved patterns of SPs excitation and emission on gold nanostructure sample and the angle-resolved fluorescence spectrum of dye molecules on two-dimensional periodic nanostructure substrate are acquired.