To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combinin...To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combining the unsteady continuity equation and numerical calculation method.Through the model,the contribution of the distribution Bragg reflec-tion structure and graded-bandgap emission layer to the temporal response are investigated.Meanwhile,the relationships between the temporal response characteristics of the laminated GaAs-based photocathode and different structural parame-ters are also analyzed,including average electron decay time,emission layer thickness,and incident light wavelength.It is found that the introduction of distribution Bragg reflection(DBR)layer solves the discrepancy between the absorption capability of the emission layer and the temporal response.Moreover,the distributed Bragg reflection layer can improve the time response by optimizing the initial photoelectron distribution.The improvement effect of the DBR layer on the temporal response is enhanced with the emission layer thickness decreasing or the incident light wavelength increasing.These results explain the effect of the DBR layer of the photocathode on the dynamic characteristics,which can offer a new insight into the dynamic research of GaAs-based photocathode.展开更多
The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers o...The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers of both the p-and n-DBR mirrors are analysed by combining the thermionic emission model and the finite difference method.In the meantime,the intrinsic resistance of the DBR material system is calculated to make a comparison with the junction resistance.The minimal values of series resistances of the graded p-and n-type DBR mirrors and the lateral temperature-dependent resistance variation are calculated and discussed.The result indicates the potential to optimize the design of the DBR reflectors of the 980-nm VCSELs.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U2141239 and 61771245)the Fund from the Science and Technology on Low-Light-Level Night Vision Laboratory of China(Grant No.J20200102).
文摘To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combining the unsteady continuity equation and numerical calculation method.Through the model,the contribution of the distribution Bragg reflec-tion structure and graded-bandgap emission layer to the temporal response are investigated.Meanwhile,the relationships between the temporal response characteristics of the laminated GaAs-based photocathode and different structural parame-ters are also analyzed,including average electron decay time,emission layer thickness,and incident light wavelength.It is found that the introduction of distribution Bragg reflection(DBR)layer solves the discrepancy between the absorption capability of the emission layer and the temporal response.Moreover,the distributed Bragg reflection layer can improve the time response by optimizing the initial photoelectron distribution.The improvement effect of the DBR layer on the temporal response is enhanced with the emission layer thickness decreasing or the incident light wavelength increasing.These results explain the effect of the DBR layer of the photocathode on the dynamic characteristics,which can offer a new insight into the dynamic research of GaAs-based photocathode.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974012)
文摘The resistance characteristics of a continuously-graded distributed Bragg reflector（DBR） in a 980-nm verticalcavity surface-emitting laser（VCSEL） are modeled in detail.The junction resistances between the layers of both the p-and n-DBR mirrors are analysed by combining the thermionic emission model and the finite difference method.In the meantime,the intrinsic resistance of the DBR material system is calculated to make a comparison with the junction resistance.The minimal values of series resistances of the graded p-and n-type DBR mirrors and the lateral temperature-dependent resistance variation are calculated and discussed.The result indicates the potential to optimize the design of the DBR reflectors of the 980-nm VCSELs.
