Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in ...Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in improving VCSEL performance,the role of cavity geometry in optimizing key optical characteristics remains insufficiently explored.This study systematically examines how distinct cavity geometries—circular,square,D-shaped,mushroom-shaped,and pentagonal—affect both the static and dynamic properties of broad-area VCSELs.We analyze their effects on optical power,multimode behavior,beam profile,spatial coherence,and polarization dynamics.Our results show that breaking the continuous rotational symmetry of the cavity effectively increases gain utilization and power,changes the multimode lasing characteristics,shapes the beam,and modifies the polarization.Notably,the pentagonal VCSEL exhibits more than twice the optical power density of its circular counterpart.It also supports the highest number of modes and the fastest mode dynamics,driven by strong mode interaction.These properties make it a strong candidate for high-speed entropy generation.Mushroom-shaped VCSELs demonstrate high power and low spatial coherence,making them ideal for speckle-free imaging and illumination applications.Meanwhile,D-shaped VCSELs provide the most stable polarization and controllable multimode behavior with high power,showcasing their potential for applications that require stable and low-coherence light sources.This study offers a comprehensive analysis of the impact of cavity geometry on VCSEL performance,which provides insights for optimizing VCSEL designs tailored to diverse applications that require distinct properties with broad applicability to advanced imaging,sensing,optical coherence tomography,high-speed communication,and other photonic technologies.展开更多
Various high-performance wearable sensors have attracted increasing interest from researchers for the accurately monitoring of physiological signal.Wearable temperature sensors,as an important part of wearable sensors...Various high-performance wearable sensors have attracted increasing interest from researchers for the accurately monitoring of physiological signal.Wearable temperature sensors,as an important part of wearable sensors,allow accurate access to temperature information and are widely used in fields such as intelligent robotics and health monitoring.Improving key characteristics of wearable electronics is essential to expanding their application areas.In this study,we develop a wearable temperature sensor that leverages an ion capture and release dynamics mechanism,based on hydrogen bonding,to enhance the sensitivity of a wearable temperature sensor via a novel silica-in-ionogel composite.The developed sensor demonstrates ultra-high temperature sensitivity(0.008℃)and excellent stability.Departing from conventional healthcare applications of physiological temperature monitoring,our work pioneers a novel paradigm to mirror our subjective thermal sensations,utilizing sensor data that exceeds the sensitivity of the human skin.As proof of concept,we demonstrate the sensor’s potential of apparent temperature monitoring for the purpose of establishing a smart dynamic temperature control system,with the aim of keeping the human in a thermally comfortable environment throughout.Our work opens up a potential application scenario for wearable temperature sensors in personalized temperature regulation.展开更多
基金supported by the King Abdullah University of Science and Technology(KAUST)under the Grant of Transition Award in Semiconductors:Grant No.FCC/1/5939,the KAUST Center of Excellence for Renewable Energy and Storage Technologies(CREST):Grant No.FCC/1/5937,and the KAUST Grant Nos.RFS-OFP2023-5534,BAS/1/1614-01-01,ORA-2022-5313,and ORFS-2022-CRG11-5079.The authors acknowledge the use of the KAUST Nanofabrication Core Lab and the KAUST Imaging and Characterization Core Lab facilities.
文摘Vertical-cavity surface-emitting lasers(VCSELs)are essential in modern optoelectronic systems,driving applications in high-speed optical communications,3D sensing,and LiDAR.While significant progress has been made in improving VCSEL performance,the role of cavity geometry in optimizing key optical characteristics remains insufficiently explored.This study systematically examines how distinct cavity geometries—circular,square,D-shaped,mushroom-shaped,and pentagonal—affect both the static and dynamic properties of broad-area VCSELs.We analyze their effects on optical power,multimode behavior,beam profile,spatial coherence,and polarization dynamics.Our results show that breaking the continuous rotational symmetry of the cavity effectively increases gain utilization and power,changes the multimode lasing characteristics,shapes the beam,and modifies the polarization.Notably,the pentagonal VCSEL exhibits more than twice the optical power density of its circular counterpart.It also supports the highest number of modes and the fastest mode dynamics,driven by strong mode interaction.These properties make it a strong candidate for high-speed entropy generation.Mushroom-shaped VCSELs demonstrate high power and low spatial coherence,making them ideal for speckle-free imaging and illumination applications.Meanwhile,D-shaped VCSELs provide the most stable polarization and controllable multimode behavior with high power,showcasing their potential for applications that require stable and low-coherence light sources.This study offers a comprehensive analysis of the impact of cavity geometry on VCSEL performance,which provides insights for optimizing VCSEL designs tailored to diverse applications that require distinct properties with broad applicability to advanced imaging,sensing,optical coherence tomography,high-speed communication,and other photonic technologies.
基金supported by the Natural Science Foundation Committee of China(NSFC,No.62271227 and No.62020106006)the National Key R&D Program of China(2021YFB3200400)+1 种基金the program of“Medicine+X”Interdisciplinary Innovation Team of Bethune Medical Department,Jilin University(2022JBGS09)the Graduate Innovation Fund of Jilin University(2024CX088).
文摘Various high-performance wearable sensors have attracted increasing interest from researchers for the accurately monitoring of physiological signal.Wearable temperature sensors,as an important part of wearable sensors,allow accurate access to temperature information and are widely used in fields such as intelligent robotics and health monitoring.Improving key characteristics of wearable electronics is essential to expanding their application areas.In this study,we develop a wearable temperature sensor that leverages an ion capture and release dynamics mechanism,based on hydrogen bonding,to enhance the sensitivity of a wearable temperature sensor via a novel silica-in-ionogel composite.The developed sensor demonstrates ultra-high temperature sensitivity(0.008℃)and excellent stability.Departing from conventional healthcare applications of physiological temperature monitoring,our work pioneers a novel paradigm to mirror our subjective thermal sensations,utilizing sensor data that exceeds the sensitivity of the human skin.As proof of concept,we demonstrate the sensor’s potential of apparent temperature monitoring for the purpose of establishing a smart dynamic temperature control system,with the aim of keeping the human in a thermally comfortable environment throughout.Our work opens up a potential application scenario for wearable temperature sensors in personalized temperature regulation.
