Fiber optic transceiver is a device used for the transition of light and electricity in fiber optical communication. It is made up of functional circuit, optical interface and optoelectronic device, among which optoelectronic device is the most important part. Optoelectronic device has two functions: transmitting the electricity signal into light signal and receiving light signal into electricity signal. According to different capacity needs, there are different connectors of fiber optic transceivers , and the most commonly used ones are SFP, SFP+ and XFP. The parameters of central wavelength, transmission rate and transmission range will also limit the functions of fiber optic transceivers.