Study Of All-Optical Logic Technolohy Based On LOA, RTD And Trans-Directional Coupler

With the rapid development of the high speed and large capacity modern communication systerm,requirements of devices which are used in different communication systerms are more and more high.For example,high speed and low power circuits require electronic logic devices with high performance and small size,the growing variety of communication services need the microwave coupled devices with higher frequencies,and the high speed and large capacity optical communication needs high speed all-optical logic devices used in all-optical signal processing.Logic operation device is the basic device in the communication systerm,it is necessary to master the independent intellectual property rights of these devices.Therefore,depth research on advanced logic devices in different communication system has larger significance.In this thesis,we mainly study the linear optical amplifier(LOA)in the optical field,resonant tunneling diode(RTD)and trans-directional(TRD)coupler in the electronic field.Based on the cross-gain modulation(XGM),all-optical logic gate operation was realized by using LOA,and the effects of different parameters on the output of logic gates were discussed.The relationships among the resistances of single RTD were studied,and intrinsic negative resistance of RTD has been defined and measured.Combined with the principle of periodic load coupling line,the function of the TRD coupler was deduced by using the conditions of odd-even mode impedance and phase velocity,and the design model of the slotted TRD coupler was proposed.TRD coupler sample was developed,and the experimental research verified the effectiveness and correctness of the model.Specific research contents and innovations are as follows:1.A theoretical model of LOA-XGM was established based on velocity equation.The theoretical model was studied to achieve all-optical logic “AND” and “NOR” operation based on LOA-XGM effect.The theoretical model was proposed to achieve all-optical logic “XOR” operation,which was realized by using multiple LOA.Using Simulink software simulation verified the validity of the theoretical model.2.Based on the XGM effect,the “XNOR” model was established by reducing the number of LOA.An excellent logic output results was obtained by optimizing the parameters of input or device's.3.The relationships among the resistances of RTD were studied systematically.On the basis of measuring the series resistance of RTD by the external resistance method,the intrinsic negative resistance of RTD was redefined and measured according to the principle of positive and negative resistance compensation.The relationship among the series resistance,intrinsic negative resistance and measured negative resistance was established.Based on the measurement of the RTD sample tube,the obtained experimental data well confirmed the relationship among these resistances we proposed.4.With deep research on the working mechanism of the TRD coupler with periodic load coupled line structure,the operation of TRD coupler was deduced.In order to overcome the problem that the odd-even mode impedance and phase velocity these two conditions was difficult to meet,using periodic load coupling lines to replace the original coupling line,adjusting the period of the new coupling line and the load impedance to satisfy the conditions required for the operation of the TRD coupling.5.By changing the structure of the coupler,a slots design on the four port was presented.The slotted model of the periodic load TRD coupler was simulated by using HFSS software,and the S parameters were analyzed.Compared with the S parameters of the non-slotted TRD coupler,this new model can reduce the loss and improve the isolation.The TRD coupler was fabricated and measured,the experimental data was consistent with the simulation results,and the experimental research verified the validity of the designing scheme.