Then beginning with information theory,the effects of channel parameters such as pulse time-domain extension,unit pulse power,and the number of time-slots transmitting information per unit symbol interval on the channel capacity of laser PPM have been studied by adopting soft decision demodulation in certain background noise.

The Application of Pulse-expanding Circuit Based on the FPGA;

The designing and implementation of monostable pulse-expanding circuit based on FPGA device;

Manufacture of chromatic dispersion impulse expanding analytic device in optical fiber;

The basic theory of chromatic dispersion in optical fibers is discussed and the pulse expanding is analyzed on emphasis.

Identifing target with pulse stretching characteristic;

The temporal variation of the inversion density,the cavity loss(including laser output) and the photon density were analyzed by theoretical calculation in a electro-optical Qswitched ruby laser,and then the conditions of laser pulse stretching were calculated.

Effect on pulse broadening due to first-order polarization mode dispersion compensation;

The experiment results prove that the pulse broadening for an optical pulse propagating along several hundreds meters optical fibers contained single mode or multi-mode during propagation is allowed.

Propagation induced pulse broadening of single event transient is studied by SPICE simulation.