The optical absorption of GaAs nanorings （NRs） under adc electric field and a terahertz （THz） ac electric field applied in the plane containing the NRs is investigated theoretically. The NRs may enclose some magne...The optical absorption of GaAs nanorings （NRs） under adc electric field and a terahertz （THz） ac electric field applied in the plane containing the NRs is investigated theoretically. The NRs may enclose some magnetic flux in the presence of a magnetic field perpendicular to the NRs plane. Numerical calculation shows that the excitonic effects are essential to correctly describe the optical absorption in NRs. The applied lateral THz electric field, as well as the dc field leads to reduction, broadening and splitting of the exciton peak. In contrast to the presence of a dc field, significant optical absorption peak arises below the zero-field bandgap in the presence ofa THz electric field at a certain frequency. The optical absorption spectrum depends evidently on the frequency and amplitude of the applied THz field and on the magnetic flux threading the NRs. This promises potential applications of NRs for magneto-optical and THz electro-optical sensing.展开更多
As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manuf...As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high temperatures.Finally, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.展开更多
We calculate the exciton binding energy and interband optical absorption in a rectangular coupled quantum wire under the hydrostatic pressure in the effective-mass approximation, using the variational approach. It is ...We calculate the exciton binding energy and interband optical absorption in a rectangular coupled quantum wire under the hydrostatic pressure in the effective-mass approximation, using the variational approach. It is found that the interband optical absorption strongly depend on the hydrostatic pressure and the coupling parameter, and that the magnitude of the absorption coefficient for the HH1-E1 transition in the coupled quantum wire is larger than that of the single quantum wire.展开更多
In this paper,for an inhomogeneous material in which the thermal conductivity varies as a function of depth,an efficient treatment is proposed to inversely calculate the depth distri- bution of optical- absorption c...In this paper,for an inhomogeneous material in which the thermal conductivity varies as a function of depth,an efficient treatment is proposed to inversely calculate the depth distri- bution of optical- absorption coefficientby the surface temperature of the material.It is demon- strated that the results of inverse computation by that method are more similar to the experi- mental ones measured by some destructive method.Thus,the treatmentis more feasible to non- destructively estimate the distribution.展开更多
Considering the Coulomb many-body interactions, we investigate the intersubband optical processes of the quantum well by using the semiconductor Bloch equations. We calculate the evolution of intersubband absorption s...Considering the Coulomb many-body interactions, we investigate the intersubband optical processes of the quantum well by using the semiconductor Bloch equations. We calculate the evolution of intersubband absorption spectral line shape as a function of lattice temperature and electron density. It is found that the coupling of intersubband plasmons can reduce and red-shift the lower energy resonance, simultaneously enhance and blue-shift the higher energy resonance. The dependence of cascading resonances on temperature and electron density is also discussed.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10390161 and 30370420.
文摘The optical absorption of GaAs nanorings （NRs） under adc electric field and a terahertz （THz） ac electric field applied in the plane containing the NRs is investigated theoretically. The NRs may enclose some magnetic flux in the presence of a magnetic field perpendicular to the NRs plane. Numerical calculation shows that the excitonic effects are essential to correctly describe the optical absorption in NRs. The applied lateral THz electric field, as well as the dc field leads to reduction, broadening and splitting of the exciton peak. In contrast to the presence of a dc field, significant optical absorption peak arises below the zero-field bandgap in the presence ofa THz electric field at a certain frequency. The optical absorption spectrum depends evidently on the frequency and amplitude of the applied THz field and on the magnetic flux threading the NRs. This promises potential applications of NRs for magneto-optical and THz electro-optical sensing.
基金supported by the National Key Research and Development Program of China(No.2017YFB0503200)the National Natural Science Foundation of China(Nos.61675185 and 61875250)+3 种基金the Natural Science Foundation of Shanxi Province(No.201701D121065)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provincethe Program for the Top Young and Middle-Aged Innovative Talents of HigherLearning Institutions of Shanxisponsored by the Fund for Shanxi ‘1331 Project’ Key Subject Construction
文摘As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high temperatures.Finally, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.
文摘We calculate the exciton binding energy and interband optical absorption in a rectangular coupled quantum wire under the hydrostatic pressure in the effective-mass approximation, using the variational approach. It is found that the interband optical absorption strongly depend on the hydrostatic pressure and the coupling parameter, and that the magnitude of the absorption coefficient for the HH1-E1 transition in the coupled quantum wire is larger than that of the single quantum wire.
基金Supported by the Doctoral Fund of the Education Ministry of China(1 9990 3 3 5 1 6 ) and the NationalNatural Science Foundation of China(1 0 0 71 0 73 )
文摘In this paper,for an inhomogeneous material in which the thermal conductivity varies as a function of depth,an efficient treatment is proposed to inversely calculate the depth distri- bution of optical- absorption coefficientby the surface temperature of the material.It is demon- strated that the results of inverse computation by that method are more similar to the experi- mental ones measured by some destructive method.Thus,the treatmentis more feasible to non- destructively estimate the distribution.
基金Supported by the National Fund for Distinguished Young Scholars of China （60425415）, the Major Project of the National Natural Science Foundation of China （10390162）. the Special Funds for Major State Basic Research of China （G20000683）, and the Shanghai Municipal Commission of Science and Technology （03JC14082）.
文摘Considering the Coulomb many-body interactions, we investigate the intersubband optical processes of the quantum well by using the semiconductor Bloch equations. We calculate the evolution of intersubband absorption spectral line shape as a function of lattice temperature and electron density. It is found that the coupling of intersubband plasmons can reduce and red-shift the lower energy resonance, simultaneously enhance and blue-shift the higher energy resonance. The dependence of cascading resonances on temperature and electron density is also discussed.
