With the development of information technology, people expect to obtain required information conveniently at any time, anywhere, and in any way. Because conventional wired or wireless communication can no longer meet increasing communication needs, new communication methods are being explored. Free space optical (FSO) communication is a technology that combines optical and wireless communication; it uses light as a carrier to transmit information without using a wired channel as a transmission medium. Compared with other types of wireless communication, it has the advantages of not requiring a frequency license, high frequency bandwidth, low cost, good confidentiality, low bit error rate, fast installation, resistance to electromagnetic interference, flexibility, convenient networking, and so on.