A cascaded-cavity photodetector with subwavelength metallic slit is proposed to enhance responsivity and response speed simultaneously.Responsivity enhancement depends on light transmittance increased by using a subwa...A cascaded-cavity photodetector with subwavelength metallic slit is proposed to enhance responsivity and response speed simultaneously.Responsivity enhancement depends on light transmittance increased by using a subwavelength metallic slit plasmonic mode resonant cavity;it also relies on quantum efficiency improved by adopting a resonant cavity enhanced structure.Response speed improvement is due to low capacitance of metal-slit-metal and thin absorption layers.In the cascaded-cavity structure,the subwavelength metallic slit plays a vital role in performance improvements.Simulation results show that,for the optimized slit structure,responsivity enhancement of 80 times can be achieved compared to the conventional structure.In addition,response bandwidth of the optimized structure can reach 150 GHz.展开更多
We carry out a detailed theoretical study on THz coherent generation in an LTG-GaAs photomixer with a resonant-cavity-enhanced (RCE) structure.In the structure,an improvement in THz output can be achieved by increasin...We carry out a detailed theoretical study on THz coherent generation in an LTG-GaAs photomixer with a resonant-cavity-enhanced (RCE) structure.In the structure,an improvement in THz output can be achieved by increasing the quantum effciency.Under optimized structure parameters,the maximum quantum efficiency of the RCE photomixer is 93%,which is 2.82 times higher than that of the case without an RCE structure.The corresponding THz output ratio of the two structures is found to be about eight in the whole range of the lower frequency at the same incident optical power.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 61178002.
文摘A cascaded-cavity photodetector with subwavelength metallic slit is proposed to enhance responsivity and response speed simultaneously.Responsivity enhancement depends on light transmittance increased by using a subwavelength metallic slit plasmonic mode resonant cavity;it also relies on quantum efficiency improved by adopting a resonant cavity enhanced structure.Response speed improvement is due to low capacitance of metal-slit-metal and thin absorption layers.In the cascaded-cavity structure,the subwavelength metallic slit plays a vital role in performance improvements.Simulation results show that,for the optimized slit structure,responsivity enhancement of 80 times can be achieved compared to the conventional structure.In addition,response bandwidth of the optimized structure can reach 150 GHz.
基金Supported by the National Natural Science Foundation of China under Grant No 60977044.
文摘We carry out a detailed theoretical study on THz coherent generation in an LTG-GaAs photomixer with a resonant-cavity-enhanced (RCE) structure.In the structure,an improvement in THz output can be achieved by increasing the quantum effciency.Under optimized structure parameters,the maximum quantum efficiency of the RCE photomixer is 93%,which is 2.82 times higher than that of the case without an RCE structure.The corresponding THz output ratio of the two structures is found to be about eight in the whole range of the lower frequency at the same incident optical power.
