Xiaohong Sun

Study of Eu(DBM)3phen-doped optical polymer waveguides

Eu(DBM)3phen-doped polymer optical planar waveguides with low propagation loss of 0.5 dB/cm have been fabricated. The optical properties and concentration quenching of Eu(DBM)3phen-doped poly(methyl methacrylate) (PMMA) have been studied. The Eu3+ ion in Eu(DBM)3phen-doped PMMA can be doped to high concentration (1 wt.%) without clustering. An Eu(DBM)3phen-doped polymer waveguiding film with a very smooth surface was obtained. An atomic force microscope measurement result indicates that rms surface roughness of the waveguiding film is ∼1.185 nm. The near-field fluorescence was observed on Eu(DBM)3phen-doped waveguiding film with 1-wt.% Eu3+ ions.

Nano-scale study of microstructure of Eu(DBM) 3 phen-doped poly(methyl methacrylate) by near-field scanning microscopy and optical properties

Eu(DBM) 3 phen-doped poly(methyl methacryate) (PMMA) with different doping concentration were prepared. The highest doping concentration sample (10000 ppm) was examined by near-field scanning optical microscopy (NSOM) with a resolution of 50 nm; and the result showed that there were no aggregates larger than 50 nm in the doped polymer. This result was further confirmed by optical properties of the doping material. Concentration quenching was not detected by metastable-state lifetime measurements, indicating that no aggregates existed. According to the fluorescence spectra analysis, the relative intensity ratio (R) of 5 D 0 → 7 F 2 to 5 D 0 → 7 F 1 transition was not shown to be significantly changed with the increasing of Eu 3+ content. The analysis reflected that the local structure and asymmetry in the vicinity of europium ions were not changed, and that the Eu 3+ ions in PMMA were homogeneously dispersed.

Birefringent gratings induced by polarized laser in azobenzene-doped poly(methyl methecrylate) optical fibers

Birefringence gratings induced by 532nm polarized laser in an azobenzene doped polymethyl methacrylate (PMMA) fiber and perform block were investigated. Significant photo-induced birefringence has been observed from the fiber. The maximum induced index change is about 3.1x10+MIN5) from this material. The induced birefringence was attributed to the nonlinear absorption at 532nm wavelength. It is found there is the threshold intensity of 0.29mW/cm2. The birefringence decayed little by little when laser turned off, a certain amount of saturation was remained. The dynamics process of the birefringence was studied. This birefringent grating may apply in the polarization dispersion compensation of the fiber communication.

BOUNDARY DIFFRACTION METHOD FOR APERTURE NEAR-FIELD DIFFRACTION

The boundary diffraction method is introduced to analyze the near-field diffraction of a subwavelength aperture. A self-consistent formula of boundary diffraction suitable to near field is derived. The near-field diffraction patterns of slits and circular apertures are obtained. The influence of incident light polarization on these diffraction patterns is also shown. These results are in good agreement with other theoretical and experimental results.

Study of rhodamine B-doped polymer optical waveguides by using scanning near-field optical microscopy

The rhodamine B-doped polymer optical planar waveguide with low propagation loss of 0.44 dB/cm has been fabricated and measured by using scanning near-field optical microscopy and m-line method. The mode structure, near-field topography and near-field fluorescence are obtained, respectively. This may have potential applications in the study of polymer waveguide laser and amplifier.

3D profile reconstruction using optical fiber Fizeau interferometer

In this article, a new method is introduced to reconstruct 3D profile from the 2D interferogram of Fizeau Interferometer. By using matrix optics, the interferometric mechanism is analyzed. On this bases, the relationship between the interference pattern and 3D profile is built up by fringe tracing of two interferograms of the object to be tested at two places with a certain separation. Depending on the relationship, the data profile are figured out and the 3D profile is obtained with the aid of computer.

Measurement for both vibration and deformation of microsurface by Fizeau interferometer of composite self-focus rod sensor

By using composite self-focus rod, LD-pumped frequency doubling Nd:YVO4 laser and 3D fine regulation stand, a new Fizeau-type interferometer is developed. It can apply to measuring the micro-vibration and deformation of micro- surface at the same time. The theoretical analysis and the experimental results for the interferometer of self-focus sensor are given.