Research On The Spatial Soliton Induced By Upconversion Luminescence In Nd:CBN

The formation of photorefractive spatial optical solitons is applied to the work of photorefractive effect of materials and the diffraction divergence of light beam. Based on low power, fast response and strongly nonlinear, photorefractive spatial solitons have potential application value in related field such as the optical switch, optical waveguide and optical interconnects.This paper is mainly introduced the basic structure and spectroscopy characteristics of non-photovoltaic photorefractive crystal Nd-doped calcium tungstate(Nd:CBN). Combined with related theory, studied the transmission characteristics of light beam under the electric field, translation and other perturbation. We observed the existence of photorefractive spatial optical solitons induced by luminescence. We compared the results of numerical simulation and experimental results. In this paper, the main research results can be summarized as follows:This paper sums up the basic physical parameters such as density, refractive index, Curie temperature of the crystal of Nd-doped calcium tungstate(Nd:CBN). The UV-VIS-NIR absorption spectrum was measured by spectrophotometer at room temperature. There are mainly five Neodymium ions absorption peak at 526 nm,586 nm,740 nm,802 nm and 872 nm. We measured the fluorescence spectra under the excitation of 808 nm. There are mainly two peaks at 438nm and 580nm. According to J-0 theory, using Origin software, select the absorption peak, we got the basic optical parameter such as spectral line intensity and oscillator strength. We calculated the absorption cross section of the crystal. The absorption cross section is 3.25092833×10-20cm2 at 802nm. We calculated transition probability of spontaneous radiation, emission cross section and fluorescence branching ratio. The fluorescence life of 4F3/2 level is 440μs.This paper studies the propagation properties of light beam in the Nd-doped calcium tungstate crystal(Nd:CBN). According to the characteristics of the crystal, design the experiment scheme. We observed the beam self-focusing in crystal under the action of electric field, translation. We quantitative analyzed the formation process of soliton quantified by gray analysis method showed. These will work for the next chapter.In this paper, we studied the experimental process of the photorefractive spatial soliton inspired by the pump of 808 nm in the Nd-doped calcium tungstate crystal. According to the experimental results, we can see that the pump light is wrapped in the contour fluorescence, and both have a tendency to close to each other. According to the related theories are simulated. Simulation results and experimental results are kept good aggrement.