Study On Characteristics Of Grating Based On Polymer With Thtrafluoro-azobenzene Pendants

In recent years, azobenzene polymers attracted much attention of researchers, due to its notable features such as high sensitivity, good fatigue resistance and high spatial resolution significant. In this paper, works are carried out as follows to aim at the photosensitive properties and the grating performance of polymer with tetrafluoro-azobenzene pendants.Firstly, azobenzene polymers is introduced and categorized,and its photoinduced cis-trans isomerization, birefringence, mass migration, nonlinear optics and other light response characteristics are simply explained. The research background and progresses of the azobenzene polymer in optical information processing research and application are introduced.The film forming properties of polymer with tetrafluoro-azobenzene pendants is studied on experiment. And its cis-trans isomerization characteristics are tested. The formation mechanism of the light induced surface relief gratings is introduced and applied to manufacture surface relief gratings with different conditions, which can be used for making two-dimensional surface relief gratings.This paper focuses on the research of polymer with tetrafluoro-azobenzene pendants light-induced birefringence. The formation mechanism and measurement principle of birefringence are introduced. Then the effect of the pump light intensity and pump frequency on the birefringence of the sample film is tested through experiment. According to the properties of birefringence relaxation phenomenon and erased repeatedly, a novel kind of all-optical switch composed of the polymer is proposed, experimental results are satisfactory.Birefringence grating is produced and analyzed on the basis of the photoinduced birefringence characteristics of polymer with tetrafluoro-azobenzene pendants. The diffraction light field of S-S, S-P, P-P and RCP-LCP are carried on the theoretical analysis by Jones matrix. The birefringence grating transmission matrix of four kinds of polarization combination are concluded. The production process of birefringence grating is analyzed through recording with four polarization combinations. Then the polarization conversion process is explained and analyzed through comparing with the theory. By detecting the birefringence grating with three kinds of wavelength, the polarization of diffraction light is wavelength independent is found. The phase delay of birefringence grating is calculated, it is concluded that with the increase of the cycle, phase delay of saturated gradually.