| The demand for 5G networks has brought about changes in the optical module market and promoted the continuous updating of optical transceiver products.Generally,the optical module has two ports and needs to use two optical fibers to transmit signals.The utilization rate of optical fibers is low,while the use of single fiber bidirectional(Bi Di)optical module can reduce optical fiber resources and costs.The core part of the optical module is optical transceivers,but the existing Bi Di optical transceiver have the following problems: the optical transceiver wavelength spacing is large,which does not meet the requirements of the DWDM system,and the wavelength in the optical network does not meet the self adaptability and flexibility,facing the challenges of network management and maintenance.In view of the above problems,based on the theory of single fiber bidirectional tunable technology,this thesis studies the working principle of laser,TEC and thermal tuning etalon,and deeply studies the core function of tunable Bi Di transceiver--wavelength real-time dynamic tuning.The main work of this thesis is as follows :Firstly,aiming at the problem of large optical transceiver wavelength interval and dynamic tuning,an optical emission / reception wavelength locking method based on thermal tuning etalon is proposed.The output wavelength of the laser is locked by tuning a single etalon,and then another etalon is tuned to control the emission and reception wavelength interval less than 1 nm.Aiming at the problem of network management and maintenance,the MPD handshake protocol is proposed.The output power of the local device and the opposite device is monitored in real time through the Monitor Photo Detector(MPD)as a feedback signal to manage and maintain the performance of the transceiver.Secondly,based on the above key technologies,this thesis designs a new structure of tunable single fiber bidirectional transmission component.Based on the traditional single fiber bidirectional optical transceiver,the function of coordination unit is added to realize the design of internal integrated thermal tuning etalon,handshake device and optical system.The models of coordination unit,emitter and receiver are designed,and the innovation of optical system is realized.The performance of coupling efficiency and spot size is analyzed by simulation,and the feasibility of the design scheme is verified.Then,based on the heat conduction theory,the heat dissipation structure of the laser is established.The simulation analysis shows that the heat is mainly distributed along the long direction of the vertical cavity,and the material of the heat dissipation structure and the position of the laser are optimized.After optimization,the maximum temperature of the laser is reduced by 1.083°C,and then the performance of TEC operating voltage,maximum temperature difference and TEC cold and hot end temperature is analyzed.For the thermal performance simulation of the thermal tuning etalon,the trajectory and power consumption of the heating electrode are optimized according to the simulation results,so that the maximum temperature difference in the spot area is less than 0.013°C.Compared with the temperature difference of 2.36°C in the original scheme,the temperature gradient is obviously improved.For the whole optical transceiver simulation,through the temperature control of TEC in different temperature environments,the laser drifts 1.66°C in the high temperature environment and 0.71°C in the low temperature environment.Compared with the high temperature drift of 5.29°C and the low temperature drift of 5.27°C in the TEC off state,the laser temperature drift is significantly improved.Finally,the actual sample is produced.By testing the output power,thermally tuned etalon response speed,eye diagram and spectrum,and response current performance,the results meet the expected requirements of tunable Bi Di optical transceivers. |
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