Aging is characterized by a progressive deterioration of physiological integrity,leading to impaired functional ability and ultimately increased susceptibility to death.It is a major risk factor for chronic human dise...Aging is characterized by a progressive deterioration of physiological integrity,leading to impaired functional ability and ultimately increased susceptibility to death.It is a major risk factor for chronic human diseases,including cardiovascular disease,diabetes,neurological degeneration,and cancer.Therefore,the growing emphasis on “healthy aging” raises a series of important questions in life and social sciences.In recent years,there has been unprecedented progress in aging research,particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes.In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases,we review the descriptive,conceptual,and interventive aspects of the landscape of aging composed of a number of layers at the cellular,tissue,organ,organ system,and organismal levels.展开更多
Whispering-gallery-mode(WGM) hexagonal optical micro-/nanocavities can be utilized as high-quality(Q) resonators for realizing compact-size low-threshold lasers. In this paper, the progress in WGM hexagonal micro-/nan...Whispering-gallery-mode(WGM) hexagonal optical micro-/nanocavities can be utilized as high-quality(Q) resonators for realizing compact-size low-threshold lasers. In this paper, the progress in WGM hexagonal micro-/nanocavity lasers is reviewed comprehensively. High-Q WGMs in hexagonal cavities are divided into two kinds of resonances propagating along hexagonal and triangular periodic orbits, with distinct mode characteristics according to theoretical analyses and numerical simulations;however, WGMs in a wavelength-scale nanocavity cannot be well described by the ray model. Hexagonal micro-/nanocavity lasers can be constructed by both bottom-up and top-down processes, leading to a diversity of these lasers. The ZnO-or nitride-based semiconductor material generally has a wurtzite crystal structure and typically presents a natural hexagonal cross section. Bottom-up growth guarantees smooth surface faceting and hence reduces the scattering loss effectively.Laser emissions have been successfully demonstrated in hexagonal micro-/nanocavities synthesized with various materials and structures. Furthermore, slight deformation can be easily introduced and precisely controlled in top-down fabrication, which allows lasing-mode manipulation. WGM lasing with excellent singletransverse-mode property was realized in waveguide-coupled ideal and deformed hexagonal microcavity lasers.展开更多
Chaotic semiconductor lasers have been widely investigated for generating unpredictable random numbers,especially for lasers with external optical feedback.Nevertheless,chaotic lasers under external feedback are hinde...Chaotic semiconductor lasers have been widely investigated for generating unpredictable random numbers,especially for lasers with external optical feedback.Nevertheless,chaotic lasers under external feedback are hindered by external feedback loop time,which causes correlation peaks for chaotic output.Here,we demonstrate the first self-chaotic microlaser based on internal mode interaction for a dual-mode microcavity laser,and realize random number generation using the self-chaotic laser output.By adjusting mode frequency interval close to the intrinsic relaxation oscillation frequency,nonlinear dynamics including self-chaos and period-oscillations are predicted and realized numerically and experimentally due to internal mode interaction.The internal mode interaction and corresponding carrier spatial oscillations pave the way of mode engineering for nonlinear dynamics in a solitary laser.Our findings provide a novel and easy method to create controllable and robust optical chaos for high-speed random number generation.展开更多
Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a t...Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a twodimensional finite element method for realizing stable dual-mode lasing. The microresonator features a smooth boundary and the same symmetry as a square resonator. A small variable-curvature microresonator with a radius of 4 μm can support the fundamental four-bounce mode and the circular-like mode simultaneously, with quality factors up to the order of 10~4 and 10~5, respectively. The dual modes in the phase space of the Poincarésurface of sections distribute far from each other and can maintain enough stability for dual-mode lasing.Furthermore, the refractive index and waveguide can modulate the dual-mode wavelength difference and quality factors efficiently thanks to the spatially separated fields of these two modes.展开更多
基金supported by the National Natural Science Foundation of China(31871380,32000500,32070730,32170756,32170804,81330008,81671377,81725010,81725010,81872874,81921006,81922027,81971312,81991512,82030041,82103167,82122024,82125009,82125011,82130044,91749126,91949101,91949207,92049302)the National Key Research and Development Program of China(2017YFA0506400,2018YFA0800200,2018YFA0800700,2018YFA0900200,2018YFC2000100,2018YFC2000400,2018YFE-0203700,20192ACB70002,2019YFA0802202,2020YFA0113400,2020YFA0803401,2020YFA0804000,2020YFC2002800,2020YFC-2002900,2021ZD0202401)+11 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16010100,XDA16010603,XDA16020400,XDB29020000,XDB39000000,XDB39000000,XDB39030300)the China Association for Science and Technology(2021QNRC001)the Beijing Municipal Science and Technology Commission(Z200022)the Natural Science Foundation of Shanghai(21JC1406400)the Key Programs of the Jiangxi ProvinceChina(20192ACB70002)the“Shu Guang”Project supported by the Shanghai Municipal Education Commission and Shanghai Education Development Foundation(19SG18)the Shanghai Sailing Program(22YF1434300)the Research Project of Joint Laboratory of University of Science and Technology of China and Anhui Mental Health Center(2019LH03)the Fundamental Research Funds for the Central Universities(WK2070210004)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(YESS20210002)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022083)。
文摘Aging is characterized by a progressive deterioration of physiological integrity,leading to impaired functional ability and ultimately increased susceptibility to death.It is a major risk factor for chronic human diseases,including cardiovascular disease,diabetes,neurological degeneration,and cancer.Therefore,the growing emphasis on “healthy aging” raises a series of important questions in life and social sciences.In recent years,there has been unprecedented progress in aging research,particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes.In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases,we review the descriptive,conceptual,and interventive aspects of the landscape of aging composed of a number of layers at the cellular,tissue,organ,organ system,and organismal levels.
基金Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDJ-SSW-JSC002)National Natural Science Foundation of China(NSFC)(61527823,61875188)
文摘Whispering-gallery-mode(WGM) hexagonal optical micro-/nanocavities can be utilized as high-quality(Q) resonators for realizing compact-size low-threshold lasers. In this paper, the progress in WGM hexagonal micro-/nanocavity lasers is reviewed comprehensively. High-Q WGMs in hexagonal cavities are divided into two kinds of resonances propagating along hexagonal and triangular periodic orbits, with distinct mode characteristics according to theoretical analyses and numerical simulations;however, WGMs in a wavelength-scale nanocavity cannot be well described by the ray model. Hexagonal micro-/nanocavity lasers can be constructed by both bottom-up and top-down processes, leading to a diversity of these lasers. The ZnO-or nitride-based semiconductor material generally has a wurtzite crystal structure and typically presents a natural hexagonal cross section. Bottom-up growth guarantees smooth surface faceting and hence reduces the scattering loss effectively.Laser emissions have been successfully demonstrated in hexagonal micro-/nanocavities synthesized with various materials and structures. Furthermore, slight deformation can be easily introduced and precisely controlled in top-down fabrication, which allows lasing-mode manipulation. WGM lasing with excellent singletransverse-mode property was realized in waveguide-coupled ideal and deformed hexagonal microcavity lasers.
基金supported by the National Natural Science Foundation of China(6193501861874113)Strategic Priority Research Program,Chinese Academy of Sciences(0483000000)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDJ-SSW-JSC002).
文摘Chaotic semiconductor lasers have been widely investigated for generating unpredictable random numbers,especially for lasers with external optical feedback.Nevertheless,chaotic lasers under external feedback are hindered by external feedback loop time,which causes correlation peaks for chaotic output.Here,we demonstrate the first self-chaotic microlaser based on internal mode interaction for a dual-mode microcavity laser,and realize random number generation using the self-chaotic laser output.By adjusting mode frequency interval close to the intrinsic relaxation oscillation frequency,nonlinear dynamics including self-chaos and period-oscillations are predicted and realized numerically and experimentally due to internal mode interaction.The internal mode interaction and corresponding carrier spatial oscillations pave the way of mode engineering for nonlinear dynamics in a solitary laser.Our findings provide a novel and easy method to create controllable and robust optical chaos for high-speed random number generation.
基金National Natural Science Foundation of China(NSFC)(61235004,61377105,61527823)
文摘Stable dual-mode semiconductor lasers can be applied for the photonic generation of microwave and terahertz waves. In this paper, the mode characteristics of a variable curvature microresonator are investigated by a twodimensional finite element method for realizing stable dual-mode lasing. The microresonator features a smooth boundary and the same symmetry as a square resonator. A small variable-curvature microresonator with a radius of 4 μm can support the fundamental four-bounce mode and the circular-like mode simultaneously, with quality factors up to the order of 10~4 and 10~5, respectively. The dual modes in the phase space of the Poincarésurface of sections distribute far from each other and can maintain enough stability for dual-mode lasing.Furthermore, the refractive index and waveguide can modulate the dual-mode wavelength difference and quality factors efficiently thanks to the spatially separated fields of these two modes.