Basing on the measurement of pulse time-of-flight, 3D imaging LADAR have ability to obtain the profile of target surface. As the convolution results of impulse response function of footprint and probe pulse, the reflected pulse will distort if the footprint contain a variety of distances. After discriminate process, this distort brings in a time error for distance measurement, which becomes the anamorphose on system imaging further more. According to the discussion of time-dependent scattering cross section, this kind of anamorphose is mainly decided by the slope of target surface when the system parameters and target distance are determined. A compensation method for height error based on detected slope has been put forward. First of all, the slope distribution of detected surface could be calculated from the point cloud data by two-way difference method. Then, the approximate compensation height error will be obtained, according to the slope-error relationship by assuming that each footprint be a tilting plane. After adding to the detected data, the first approximate target surface data has been acquired. The compensation result will approaching the real value by repeating the three steps above. As an example, simulation analysis of Gaussian pulse imaging detection has been given. The result shows that this compensation method is effective and efficient.
A improved theoretical model for wavelength conversion into which the mutual coupling parameter is introduced is
present. The bit error rate of wavelength conversion are analyzed and confirmed by value simulation.
With the improved theoretical model for wavelength conversion, we demonstrate that the characteristics of wavelength conversion such as extinction ratio, signal-noise ratio and bit error rate is relative to the mutual coupling parameter introduced into the rate equations.
As the key apparatus, the All optical Wavelength Converter (AOWC) will play an important role in future optical communication and optical signal processing system. In this paper, switching characteristics of wavelength converter based on saturable absorber in semiconductor lasers will be researched. This kind of conversion mechanism possesses some advantage, such as simple structure, low cost, high stability and so on. This paper is organized as follows: Firstly, utilizing rate equations, a new theoretical model on wavelength conversion based on saturable absorber is put forward. Nextly, the frequency modulation response of wavelength conversion will be discussed under the small-signal analysis based on the theoretical model. Lastly, Numerical value solution results will be given out when external signal light injects in saturable absorber region of semiconductor lasers. The characteristics of wavelength conversion are simulated in different optical parameters including the injection current, the input signal optical power and bit rate. Those results are useful to realization and the optimal design of the wavelength converter based on saturable absorber.
As the key apparatus, the All optical Wavelength Converter (AOWC) will play an important role in future optical communication system. In this paper, a theoretical model based on mutual coupling effect of laser modes for all-optical wavelength converter in single-model homogeneously broaden laser is presented. With the theory the paper analyze the stability of single-model homogeneously broaden lasers and the influence on its characteristics when there is parameters variety. Numerical value of saw tooth wave is given also. Those results are useful to realization and the optimal design of the wavelength converter.