Study Of All Optical Logic Gate Of Based On Cross-Gain Modulation In LOA

All optical logic is the key devices of optical packet switching system, optical calculation and great capacity transmission which should be influenced heavily in the future. Cross-gain modulation (XGM) have many advantages, such as small chirp, high signal noise rate (SNR) , high extinction rate (ER) and convenient for integration. At present, many researches of logic gate which based on XGM of semiconductor optical amplifier (SOA) have been done. However, because of the linear gain characteristic, LOA is quite suit for wavelength conversion and optical logic function, and achieving higher capacity and rate information processing than traditional SOA.The basic characteristics and logic gate of LOA was studied. Firstly, a theoretical model of LOA-XGM is established based on velocity equation, The gain, extinction rate (ER) and chirp characteristics are analyzed particularly using this model. Secondly, based on XGM, numeral simulation realized the output results of logic NOR operation, using Simulink for setting up a model of connect. LOA is presented to the influences of output results with the different input current group. Finally, based on logic NOR gate, a model of all-optical logic AND gate is presented, with the excellence of the Simulink modeling, which is convenient for amending. The carrier consistency is changed with time and the influences of output results with different parameters of LOA are analyzed, they are used for the purpose of optimizing design.The results show that owing to the existence of vertical-cavity laser (VCL), the gain fluctuation of LOA is smaller than SOA's, also the gain recovery time is shorter. Lower probe power and suitable wavelength spans, which between pump and probe, and the input current have the advantages to achieve the higher output ER. But lower probe power and higher pump power in certain spectrums can also increase chirp, so suitable choice of these parameters can achieve balance of ER and chirp. The distortion of all-optical logic operation of LOA is smaller than all-optical logic operation of SOA. Proper input current groups have the advantages to achieve better logic operation effect. In the logic AND operation of LOA, proper wavelength scope of probe and pump, and higher power of the input signal A have the advantages to achieve better logic operation effect. Compared with the output results of SOA, it is further proved that the capability of LOA is more excellent than SOA.