We demonstrate the double-Brillouin-frequency spaced multiwavelength generation at room temperature by using a simple ring Brillouin-erbium fiber laser.The Brillouin pump is pre-amplified before entering the single-mo...We demonstrate the double-Brillouin-frequency spaced multiwavelength generation at room temperature by using a simple ring Brillouin-erbium fiber laser.The Brillouin pump is pre-amplified before entering the single-mode fiber,the odd Stokes and even Stokes are amplified in two opposite directions.All amplification provided by a home-made bi-directional operation erbium-doped fiber may achieve high intensity of Brillouin Stokes that leads to the homogenous gain saturation.Twelve even Stokes and thirteen odd Stokes with a wavelength spacing of 0.172 nm(20 GHz)are simultaneously obtained for 6 dBm Brillouin pump power and 120 mW pump power at 980 nm.The influence of different Brillouin and erbium-doped-fiber pump powers on multiwavelength and tuning range are investigated in detail.展开更多
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
Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneousl...Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneously support the single-mode propagation of both a pump wave(1550 nm)and a second harmonic wave(775 nm).As a result of the strong confinement and intensive nonlinear effect in the PPLNOI rib waveguide,the calculated results indicate that a second-harmonic generation conversion efficiency of 400%W^(-1)·cm^(-2) can be achieved at a wavelength of 1550 nm,almost 2.6 times higher than the widely applied reverse proton-exchanged waveguide(150%W^(-1)·cm^(-2)).展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 60977044,61008041 and 11105049the Natural Science Foundation of Hubei Province under Grant No 2011CDC010.
文摘We demonstrate the double-Brillouin-frequency spaced multiwavelength generation at room temperature by using a simple ring Brillouin-erbium fiber laser.The Brillouin pump is pre-amplified before entering the single-mode fiber,the odd Stokes and even Stokes are amplified in two opposite directions.All amplification provided by a home-made bi-directional operation erbium-doped fiber may achieve high intensity of Brillouin Stokes that leads to the homogenous gain saturation.Twelve even Stokes and thirteen odd Stokes with a wavelength spacing of 0.172 nm(20 GHz)are simultaneously obtained for 6 dBm Brillouin pump power and 120 mW pump power at 980 nm.The influence of different Brillouin and erbium-doped-fiber pump powers on multiwavelength and tuning range are investigated in detail.
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.
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2009AA03Z410。
文摘Theoretical studies on mode propagation and second harmonic generation in periodically poled MgO-doped LiNbO_(3) on an insulator(PPLNOI)rib waveguide are presented.With a special design,the waveguide can simultaneously support the single-mode propagation of both a pump wave(1550 nm)and a second harmonic wave(775 nm).As a result of the strong confinement and intensive nonlinear effect in the PPLNOI rib waveguide,the calculated results indicate that a second-harmonic generation conversion efficiency of 400%W^(-1)·cm^(-2) can be achieved at a wavelength of 1550 nm,almost 2.6 times higher than the widely applied reverse proton-exchanged waveguide(150%W^(-1)·cm^(-2)).
