Study On Bandwidth And Temperature Control Of Fiber Chaotic Lasers

The fiber chaotic laser has the characteristics of sensitivity to initial value,wide spectrum,noise-like.It has been widely used in various fields such as optical communication,optical sensing,random number generation.But the narrow bandwidth of chaotic laser greatly limits these applications.And Some achievements have been made in the research of chaotic laser bandwidth expansion,however,the higher chaotic bandwidth is still limited by the optical system and devices.The massive and complex optical structure makes the system expensive,and the stability and practical efficiency of chaotic laser is poor.A simple,low-cost and efficient broadband chaotic laser is still a major application demand.Based on that,some exploratory researches on chaotic laser bandwidth are carried out in this paper.In addition,due to the lack of research on chaotic laser control,this paper also made some explorations on fiber chaotic laser temperature control.The main research work of this paper is as follows:1、Firstly,a high bandwidth fiber chaotic laser based on pump modulation is designed.The nonlinear Kerr effect of fiber will be changed when the energy in the system is adjusted by pump source,result in changing of the nonlinear phase shift of chaotic signals,so as to adjust the chaotic bandwidth of the system.The system can generate chaotic laser bandwidth with frequency range greater than 44 GHz and standard bandwidth greater than 33.4 GHz under the condition of appropriate pump source output energy.2、Then,a high bandwidth chaotic fiber laser with adjustable wavelength based on phase-shifted fiber Bragg grating(PS-FBG)is designed.The waveform of the system is controlled by polarization controller(PC),and the phase delay of the laser is controlled by the dispersion of fiber.The disturbance of phase delay causes the randomness and instability of light intensity in the chaotic laser system,and extends the fluctuation bandwidth of laser output intensity greatly.The system can generate a standard bandwidth of 29.22 GHz at a suitable fiber length.3、Finally,a temperature control fiber chaotic laser is designed.The identifiable and highly sensitive dynamic response of chaotic signals to temperature changes are explored,which has done some exploratory work in the control of chaotic laser.