We present the influence of second order dispersion(GVD), third-order dispersion(TOD), and initial chirp on femtosecond Airy pulse propagation in Kerr media by solving the Nonlinear Schrodinger Equation with the split-step Fourier Method. In the time duration of femtosecond pulse, the effect of TOD should not be neglected. TOD can lead to waveform distortion and lower the quality of optical pulses. We also study the propagation of femtoscond Airy pulse in anomalous dispersion Kerr media. According to the numerical results, we show that when the parameter of the TOD and the propagation distance are selected as some typical values, the pulses will broadening first and then appear a process of compression. Finally, we discussed the influence of the initial pulse chirp on the propagation of the pulse profile and broadening factor.
To study the relationship between Aerosol Optical Depth (AOD) and concentration of PM<sub>2.5</sub>（Particulate Matter) basing on CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, 51 samples among the CALIPSO Level 2 aerosol profile data of local region from January to April 2014 are selected. After screening these 51 samples under the decided conditions, such as system stability and the type of the materials, the AODs of the samples are calculated. Then a linear regression model is constructed through Matlab software, in which AOD is independent variable and PM<sub>2.5</sub> is dependent variable. All the data are fit by the selected five functions: linear, logarithmic, exponential, power, and quadratic. Experimental results show that the value of correlation coefficient of the quadratic equation model is the best one among the functions. So it is feasible to monitor the concentration of PM<sub>2.5</sub> using the AOD calculated from CALIPSO Level 2 data.