Usually,an unfocused light beam,such as a paraxial Gaussian beam,can exert a force on an object along the direction of light propagation,which is known as light pressure.Recently,however,it was found that an unfocused...Usually,an unfocused light beam,such as a paraxial Gaussian beam,can exert a force on an object along the direction of light propagation,which is known as light pressure.Recently,however,it was found that an unfocused light beam can also exert an optical pulling force(OPF)on an object toward the source direction;the beam is accordingly named an optical tractor beam.In recent years,this intriguing force has attracted much attention and a huge amount of progress has been made both in theory and experiment.We briefly review recent progress achieved on this topic.We classify the mechanisms to achieve an OPF into four different kinds according to the dominant factors.The first one is tailoring the incident beam.The second one is engineering the object’s optical parameters.The third one is designing the structured material background,in which the light–matter interaction occurs,and the fourth one is utilizing the indirect photophoretic force,which is related to the thermal effect of light absorption.For all the methods,we analyze the basic principles and review the recent achievements.Finally,we also give a brief conclusion and an outlook on the future development of this field.展开更多
Laser levitated in the air may open new application scenarios,such as quantum information processing,three-dimensional display,and ultra-sensitive gas sensing et al.However,the solid-state levitated laser is yet to be...Laser levitated in the air may open new application scenarios,such as quantum information processing,three-dimensional display,and ultra-sensitive gas sensing et al.However,the solid-state levitated laser is yet to be demonstrated.Here,we develop a nebulization method to fabricate colloidal quantum dots self-assembled microspheres,which can be levitated by photophoresis provided by continuous wave lasers and photoexcited by pulsed lasers.These levitated microspheres can serve as high-quality gain media and whispering gallery mode cavities simultaneously,allowing us to demonstrate the levitated solidstate laser for the first time.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11874134 and 11474077).
文摘Usually,an unfocused light beam,such as a paraxial Gaussian beam,can exert a force on an object along the direction of light propagation,which is known as light pressure.Recently,however,it was found that an unfocused light beam can also exert an optical pulling force(OPF)on an object toward the source direction;the beam is accordingly named an optical tractor beam.In recent years,this intriguing force has attracted much attention and a huge amount of progress has been made both in theory and experiment.We briefly review recent progress achieved on this topic.We classify the mechanisms to achieve an OPF into four different kinds according to the dominant factors.The first one is tailoring the incident beam.The second one is engineering the object’s optical parameters.The third one is designing the structured material background,in which the light–matter interaction occurs,and the fourth one is utilizing the indirect photophoretic force,which is related to the thermal effect of light absorption.For all the methods,we analyze the basic principles and review the recent achievements.Finally,we also give a brief conclusion and an outlook on the future development of this field.
基金supported by the National Natural Science Foundation of China(No.52272167)the Innovation Program for Quantum Science and Technology(No.2021ZD0301603).carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Laser levitated in the air may open new application scenarios,such as quantum information processing,three-dimensional display,and ultra-sensitive gas sensing et al.However,the solid-state levitated laser is yet to be demonstrated.Here,we develop a nebulization method to fabricate colloidal quantum dots self-assembled microspheres,which can be levitated by photophoresis provided by continuous wave lasers and photoexcited by pulsed lasers.These levitated microspheres can serve as high-quality gain media and whispering gallery mode cavities simultaneously,allowing us to demonstrate the levitated solidstate laser for the first time.
