Design And Research Of Optical Logic Device Based On Microring Resonator

In the 21 st century,people have entered the information age,which is another great era after the steam age and the electrical age.The information transmission mainly depends on the microelectronic circuit technology based on semiconductor materials.With the development of integrated circuits,from the initial small-scale integrated circuits gradually developed into super large-scale circuits,and then to the emergence of super large-scale circuits,the integration of microelectronic circuits has gradually stopped due to the physical properties of electronic circuits,which is determined by the physical properties of electronic circuits.Therefore,optoelectronic integration and all-optical communication technology has gradually become a development plan to overcome this physical limitation,and has been paid more and more attention.The optoelectronic scheme or all-optical scheme has become the mainstream development direction in the future with its unique advantages.With the increasing requirements of information transmission rate in the information age,people have higher requirements for the speed of information processing and the overall integration of devices in each link.As the basic device in computer digital operation,the operation speed and performance index of logic device directly affect the information transmission ability and quality.Optical logic devices based on silicon microring resonators have attracted great attention due to their unique advantages.In this thesis,the microring resonator is taken as the research object.The advantages of microring in realizing logic operation are analyzed,and two schemes for realizing logic operation are summarized.At present,there are two schemes to realize optical logic based on microring resonator.The first is all-optical logic scheme using optical nonlinear effect.Because the advantage of photons is that photons are not charged,which are different from the physical properties of electrons,optical communication can not control the propagation direction and optical signal intensity of another beam with one beam of light,so only pump light can be used for transmission medium Irradiation changes the transmission characteristics of the transmission medium,so that the propagation direction and intensity of another beam of irradiated light signal will change accordingly,so that the output waveform of continuous wave can be controlled.Therefore,we can transfer the optical information to the modulated light without information through the pump light,and then,by changing the power combination of the output light intensity of the two beams of pump light,according to the The corresponding reflectivity and transmittance can be calculated respectively according to the power of input port and different output port,so the corresponding extinction ratio can be calculated,thus defining the logic value of the two light control signals,and finally obtainingthe digital logic relationship.The second is an electro-optic logic scheme using oriented logic,which avoids the nonlinear effect of light.The device is compact in structure,easy to integrate and low in processing cost.The operation mode and results of the steering logic are mainly determined by the optical network topology.The principle of the guiding logic is to control the switching state of the optical switch in the optical network by using the control logic number such as "0" or "1" as the high and low level.In this way,the propagation direction of light in the optical network will be affected by the optical switch,and different logic results can be obtained at the output port.In this thesis,the micro ring resonator is taken as the research object,and several kinds of optical logic devices with excellent performance are proposed and designed based on the characteristic analysis of several microring structures by the transfer matrix method.The main tasks are as follows:(1)Based on the analysis of the resonant state of microring,the working principle of several common microring structures is described.The transmission characteristics of all pass,add and drop and series double Microrings are analyzed by using the coupled mode theory of curved waveguide and transfer matrix method.Because the all pass microring can realize "not" operation,the delay,phase and transmission of all pass microring in three coupling states are simulated respectively The relationship between the responses is convenient for application in the following D flip flop.By changing the coupling distance to change the coupling coefficient,it is determined that the maximum transmission efficiency can be achieved when the coupling spacing is the same.In the actual simulation process,the introduction of graphene absorption material to absorb redundant scattered light reduces the crosstalk between structural channels and improves the output signal-to-noise ratio.(2)An optical logic device based on microring one out of two data selector is designed.The simulation results show that the structure can achieve the function of one out of two data selection.The transmission of the device output is about 0.7,with high logic contrast and fast response period of 752 fs,The size of the device structure is 39.2?m × 73?m,and the device structure is compact and easy to integrate.The realization of the logic function further improves the diversity of optical logic operation,and provides the basis for the design of more multi bit data selector in the future,which has great research significance.For the "Y" waveguide,the loss of optical signal in the waveguide is the lowest when the curvature gradient connection is used.(3)An optical D-flip-flop based on microring resonator is proposed by using the optoelectronic switching effect of microring.The basic idea is to replace the NOT gate and NAND gate circuit in the D-flip-flop with the optical logic gate device.The performance of the device is further improved by taking advantage of the advantages of low crosstalk andhigh-speed of the optical device.Finally,the proposed scheme and structure are simulated and verified in principle.