The Design And Implementation Of The Directly Modulated To Ld In The High Speed

With the development of the communication industry,higher demands have been proposed on the information transmission distance and speed.The traditional communication industry is faced with big challenges.Under this circumstance,free space optical communication has been the focus of the research in the field of new communication technologies in recent years as it is characterized with high bandwidth,low cost and free from the restriction of frequency spectrum.Atmospheric laser communication,in particular,has great application prospects in business and military fields,and it is the most effective solution to optic access network "last kilometer",because it does not need to have cables laid and enjoys high security in data transmission.In summary,the research on atmosphere laser communication is of significance in communication.This paper studies the light source module in the atmospheric laser communication,and enables the light source of semiconductor laser to achieve high-speed internal modulation and complete the high-rate information transmission of atmospheric laser communication in cooperation with other modules in the communication system.The main content shows as follows:1.It conducts a comparative research on the driving modulation circuit of laser source of first,second and third generations of atmosphere laser communication machines,and analyzes the elements that influence the transmission rate of internal modulation has been analyzed,and concludes the key techniques of high-speed internal modulation based on the performance requirements about new generation communication machines.2.It puts forward a specific scheme to realize high-speed internal modulation technique,and specifically illustrates the working state of each module in the scheme.It mainly studies the light source module and photoelectricity module in the atmosphere laser communication machine,and achieves the high-rate modulation drive of semiconductor laser and hardware circuit of photoelectricity module.3.In the paper,the experimenter debugs the circuits of driving modulation circuit and photoelectricity module,and proves the feasibility of its principle.In cooperation with the information coding and decoding of the system and information processing module,the experimenter realizes the debugging of the whole communication system.In the end,it summarizes the research scheme,discusses the problems in the debugging process and puts forward solutions.It is proven after circuit modulation that high-speed information transmission of the internal modulation technique of semiconductor laser can be realized by changing the transmission form of signals,automatic optical power control of light source and improving the integration level of the circuits.By debugging modulation modules and photoelectricity module and cooperating with the whole atmospheric communication system in work,the high-speed multiple services can be fulfilled,and the transmission speed can reach the high speed.In this way,the data,audio materials,video can be transmitted in an effective way,and the system is stable and reliable.The research outcome advances the improvement of internal modulation technique of semiconductor laser and promotes the use of atmosphere laser communication machine in China.