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 GaSb-based distributed Bragg reflection（DBR） diode laser with 23 rd-order gratings have been fabricated by conventional UV lithography and inductively coupled plasma（ICP） etching. The ICP etching conditions we...The GaSb-based distributed Bragg reflection（DBR） diode laser with 23 rd-order gratings have been fabricated by conventional UV lithography and inductively coupled plasma（ICP） etching. The ICP etching conditions were optimized and the relationship among etching depth, duty ratio and side-mode suppression ratio（SMSR） was studied. The device with a ridge width of 100 μm, gratings period of 13 μm and etching depth of 1.55 μm as well as the duty ratio of 85% was fabricated, its maximum SMSR reached 22.52 dB with uncoated cavity facets under single longitudinal operation mode at room temperature.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 Basic Research Program of China(Nos.2016YFB0402403,2014CB643903)the National Natural Science Foundation of China(Nos.61790583,61435012)
文摘The GaSb-based distributed Bragg reflection（DBR） diode laser with 23 rd-order gratings have been fabricated by conventional UV lithography and inductively coupled plasma（ICP） etching. The ICP etching conditions were optimized and the relationship among etching depth, duty ratio and side-mode suppression ratio（SMSR） was studied. The device with a ridge width of 100 μm, gratings period of 13 μm and etching depth of 1.55 μm as well as the duty ratio of 85% was fabricated, its maximum SMSR reached 22.52 dB with uncoated cavity facets under single longitudinal operation mode at room temperature.
