The Research Of Atmospheric Laser Communication System

This paper briefly told us the principle and development of atmospheric laser communication, introduced its characters and functions. And a new type of atmospheric laser communication system was used as an example which had Ethernet interface ,could transmit both sound signals and data between PCs .With experimental research data, we focused on the details of emitting and receiving devices.In the emitting part, we described the research on the selection of laser device, the drive circuit of laser diode and emitting antenna; while in the receiving part, we described the avalanche photo diode (APD) laser receiver detailedly, including the selection of photo electricity detector, preamplifier and main amplifier, and analyzed the noise character which effects on the sensitivity of the receiver. Besides, we made the qualitative analysis of the attenuation characteristic for each units as well as the secrecy characteristic. In the lab, the modulate experiment with 155Mbps signal was tested.Finally, we summarized the theories and experiments mentioned in this paper, put forward an innovative design of adding laser interface, and pointed out some work to be improved in the future.