Holographic display has attracted widespread interest because of its ability to show the complete information of the object and bring people an unprecedented sense of presence. The absence of ideal recording materials...Holographic display has attracted widespread interest because of its ability to show the complete information of the object and bring people an unprecedented sense of presence. The absence of ideal recording materials has hampered the realization of their commercial applications. Here we report that the response time of a bismuth and magnesium codoped lithium niobate(LN:Bi,Mg) crystal is shortened to 7.2 ms and a sensitivity as high as 646 cm/J. The crystal was used to demonstrate a real-time holographic display with a refresh rate of 60 Hz, as that of the popular high-definition television. Moreover, the first-principles calculations indicate that the electron mobility while Bi occupying Nb-site is significantly greater than that in Li-site, which directly induces the fast response of LN:Bi,Mg crystals when the concentration of Mg is above its doping threshold.展开更多
The ability to amplify optical signals is of paramount importance in photonic integrated circuits(PICs). Recently,lithium niobate on insulator(LNOI) has attracted increasing interest as an emerging PIC platform. Howev...The ability to amplify optical signals is of paramount importance in photonic integrated circuits(PICs). Recently,lithium niobate on insulator(LNOI) has attracted increasing interest as an emerging PIC platform. However, the shortage of efficient active devices on the LNOI platform limits the development of optical amplification. Here,we report an efficient waveguide amplifier based on erbium and ytterbium co-doped LNOI by using electron beam lithography and an inductively coupled plasma reactive ion etching process. We have demonstrated that signal amplification emerges at a low pump power of 0.1 mW, and the net internal gain in the communication band is 16.52 dB/cm under pumping of a 974 nm continuous laser. Benefiting from the efficient pumping facilitated by energy transfer between ytterbium and erbium ions, an internal conversion efficiency of 10% has been achieved, which is currently the most efficient waveguide amplifier under unidirectional pumping reported on the LNOI platform, to our knowledge. This work proposes an efficient active device for LNOI integrated optical systems that may become an important fundamental component of future lithium niobate photonic integration platforms.展开更多
Lithium niobate on insulator(LNOI) provides a platform for the fundamental physics investigations and practical applications of integrated photonics. However, as an indispensable building block of integrated photonics...Lithium niobate on insulator(LNOI) provides a platform for the fundamental physics investigations and practical applications of integrated photonics. However, as an indispensable building block of integrated photonics, lasers are in short supply. In this paper, erbium-doped LNOI laser in the 1550-nm band was demonstrated in microdisk cavities with high quality factors fabricated in batches by UV exposure, inductively coupled plasma reactive ion etching, and chemomechanical polishing. The threshold and conversion efficiency of the erbium-doped LNOI microdisk laser were measured to be lower than 1 m W and 6.5×10^(-5)%, respectively. This work will benefit the development of integrated photonics based on LNOI.展开更多
Background:The prevalence of infection with Toxoplasma gondii(T.gondii)in humans has been increasing in China due to the growing number of cats in the country.Hand,foot and mouth disease(HFMD)is a serious public healt...Background:The prevalence of infection with Toxoplasma gondii(T.gondii)in humans has been increasing in China due to the growing number of cats in the country.Hand,foot and mouth disease(HFMD)is a serious public health issue in China and still one of the leading causes of child mortality.However,little is known about the epidemiology of T.gondii infection among HFMD patients.Methods:A case–control study of 281 HFMD patients from the First People’s Hospital of Pingdingshan in Pingdingshan city,Henan province,central China,and 222 controls from Pingdingshan city was conducted.Anti-T.gondii antibodies were serologically detected using the enzyme-linked immunosorbent assay.Results:We found that the overall anti-T.gondii immunoglobulin G(IgG)antibody prevalence among HFMD patients was 12.46%,which was significantly higher than that in clinically healthy children(1.80%).The highest T.gondii seroprevalence was detected in critical cases(22.58%),followed by severe cases(11.50%),and the lowest was detected in mild cases(8.33%).Conclusion:The present study is the first survey of T.gondii seroprevalence among HFMD patients in China;12.46%were defined as seropositive.It is imperative that improved integrated measures are taken to prevent and control T.gondii infection among HFMD patients.展开更多
基金The National Key Research and Development Program of China(Grant No.2019YFA0705000)National Natural Science Foundation of China(No.12034010)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT_13R29).
文摘Holographic display has attracted widespread interest because of its ability to show the complete information of the object and bring people an unprecedented sense of presence. The absence of ideal recording materials has hampered the realization of their commercial applications. Here we report that the response time of a bismuth and magnesium codoped lithium niobate(LN:Bi,Mg) crystal is shortened to 7.2 ms and a sensitivity as high as 646 cm/J. The crystal was used to demonstrate a real-time holographic display with a refresh rate of 60 Hz, as that of the popular high-definition television. Moreover, the first-principles calculations indicate that the electron mobility while Bi occupying Nb-site is significantly greater than that in Li-site, which directly induces the fast response of LN:Bi,Mg crystals when the concentration of Mg is above its doping threshold.
基金National Key Research and Development Program of China (2019YFA0705000)National Natural Science Foundation of China (12034010, 12134007)+1 种基金Natural Science Foundation of Tianjin City (21JCQNJC00250,21JCZDJC00300)Program for Changjiang Scholars and Innovative Research Team in University (IRT_13R29)。
文摘The ability to amplify optical signals is of paramount importance in photonic integrated circuits(PICs). Recently,lithium niobate on insulator(LNOI) has attracted increasing interest as an emerging PIC platform. However, the shortage of efficient active devices on the LNOI platform limits the development of optical amplification. Here,we report an efficient waveguide amplifier based on erbium and ytterbium co-doped LNOI by using electron beam lithography and an inductively coupled plasma reactive ion etching process. We have demonstrated that signal amplification emerges at a low pump power of 0.1 mW, and the net internal gain in the communication band is 16.52 dB/cm under pumping of a 974 nm continuous laser. Benefiting from the efficient pumping facilitated by energy transfer between ytterbium and erbium ions, an internal conversion efficiency of 10% has been achieved, which is currently the most efficient waveguide amplifier under unidirectional pumping reported on the LNOI platform, to our knowledge. This work proposes an efficient active device for LNOI integrated optical systems that may become an important fundamental component of future lithium niobate photonic integration platforms.
基金supported by the National Key Research and Development Program of China (Grant No. 2019YFA0705000)the National Natural Science Foundation of China (Grant Nos. 12034010, 11734009, 11674181,11674184, and 11774182)+2 种基金the Higher Education Discipline Innovation Project (Grant No. B07013)the National Science Fund for Talent Training in the Basic Sciences (Grant No. J1103208)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT)(Grant No. IRT_13R29)。
文摘Lithium niobate on insulator(LNOI) provides a platform for the fundamental physics investigations and practical applications of integrated photonics. However, as an indispensable building block of integrated photonics, lasers are in short supply. In this paper, erbium-doped LNOI laser in the 1550-nm band was demonstrated in microdisk cavities with high quality factors fabricated in batches by UV exposure, inductively coupled plasma reactive ion etching, and chemomechanical polishing. The threshold and conversion efficiency of the erbium-doped LNOI microdisk laser were measured to be lower than 1 m W and 6.5×10^(-5)%, respectively. This work will benefit the development of integrated photonics based on LNOI.
基金This study was supported by the Key Scientific and Technological Project of Xinxiang city(no.ZG15014)the Science and Technology Research Key Project of Education Department of Henan province(no.13A310845)the Doctoral Scientific Research Activation Foundation of Xinxiang Medical University(no.XYBSKYZZ201504).
文摘Background:The prevalence of infection with Toxoplasma gondii(T.gondii)in humans has been increasing in China due to the growing number of cats in the country.Hand,foot and mouth disease(HFMD)is a serious public health issue in China and still one of the leading causes of child mortality.However,little is known about the epidemiology of T.gondii infection among HFMD patients.Methods:A case–control study of 281 HFMD patients from the First People’s Hospital of Pingdingshan in Pingdingshan city,Henan province,central China,and 222 controls from Pingdingshan city was conducted.Anti-T.gondii antibodies were serologically detected using the enzyme-linked immunosorbent assay.Results:We found that the overall anti-T.gondii immunoglobulin G(IgG)antibody prevalence among HFMD patients was 12.46%,which was significantly higher than that in clinically healthy children(1.80%).The highest T.gondii seroprevalence was detected in critical cases(22.58%),followed by severe cases(11.50%),and the lowest was detected in mild cases(8.33%).Conclusion:The present study is the first survey of T.gondii seroprevalence among HFMD patients in China;12.46%were defined as seropositive.It is imperative that improved integrated measures are taken to prevent and control T.gondii infection among HFMD patients.
