40Gbit/s CFP optical module is hot-pluggable optical modules clients, including 40Gbit/s BASE-LR4 1310nm CWDM technology-based, single-mode fiber transmission distance up to 10km. Frequency interval based ITU-T G.694.2 specification, use the 1270,1290,1310 and 330nm 4 wavelengths, each wavelength channel rate is 10.3125Gbit/s. 40Gbit/s CFP optical module is a transmission mode in a single-mode optical fiber, to support 40Gbit/s Ethernet data rate transmission over four wavelengths in each wavelength 10.3125Gbit/s, and finally the use of WDM technology to four wavelengths of light composite signal transmitted over one single-mode fiber. 40Gbit/s CFP optical modules are mainly used in MAN, it can be converted into an electrical signal input optical signal output, in order to achieve long distance transmission, but also be able to receive the optical signal into an electrical signal output.

40Gbit/s CFP optical module is mainly composed of three parts: a transmitter unit, a receiving unit and a control unit. Its basic function block diagram shown in Fig. Emitting unit by the LD (laser), LD driver and CDR (clock data recovery) circuits. Input Module 4 pairs 10.3125Gbit/s differential electrical signals through the CDR circuit and then shaping, re-timing, is received by the LD driving circuit, driving LD emit four different wavelengths of laser modulation signal with data, and then through WDM will 4 light signals combined into a single output. Received by the detector unit, two amplifier (main amplifier) ​​and the CDR circuit. At the receiving end module, the demultiplexer will be all the way 40Gbit/s optical signal is divided into four different wavelengths 10.3125Gbit/s optical signal, and through the detector to convert it into 4 weak signal. Weak signal first passes through the preamplifier, the preamplifier and the reception signal and amplified for secondary amplification, the electrical signal output from the main amplifier, thus completing the optical / electrical conversion. The control circuit part through internal communication interface on the laser APC (automatic power control), extinction ratio compensation, emitting portion soft shutdown and partial bandwidth adjustment received intelligent control, through the external communication interface may host computer to communicate with the completion of the relevant module Work state reported a detectable amount of real-time monitoring.