Ultra-confined optical fields are of great importance in fundamental optics and optical technologies.The extreme field confinement in ultra-small nanostructures presents significant challenges in direct near-field cha...Ultra-confined optical fields are of great importance in fundamental optics and optical technologies.The extreme field confinement in ultra-small nanostructures presents significant challenges in direct near-field characterization.Conventional scanning near-field optical microscopy encounters difficulties in characterizing sub-10-nm confined light fields due to significant disturbances of the optical field caused by the probe.Here,by employing a high spatial-resolved photoemission electron microscopy(PEEM),we succeeded in imaging the ultra-confined near fields of a nanoslit mode in a coupled nanowire pair(CNP)with weak disturbance for the first time and demonstrating a quasi-three-dimensional field distribution of the nanoslit mode.We also show that a PEEM image can identify fabrication defects that are influential to the confined field but are imperceptible to many other means.These results open an opportunity for weak-disturbance characterization of ultra-confined optical near fields,which is an essential step toward future optical devices or technology relying on ultra-confined light.展开更多
The compensation method aiming to reduce the irradiation on the user＇s body and to form a weak field area （a dark spot） in an antenna near region is considered. The results of the method development for the use in ...The compensation method aiming to reduce the irradiation on the user＇s body and to form a weak field area （a dark spot） in an antenna near region is considered. The results of the method development for the use in a narrow frequencies range are given. They show that under realistic conditions the compensation method allows reducing the irradiation power by a factor of 3-4 and more. The pattern changes are predictable and small, if the points of antennas placement are selected correctly. The dark spot necessity near the transmitter is not limited by mobile communication. A man often uses a low-power radio station, which is placed nearby in a vehicle, and it is necessary to protect from irradiation not only user but also other passengers. In the paper, it is shown that broadband field compensation can be achieved in various structures where the needed anti-phase fields are created either by identical antennas or by radiators located at equal distance from the compensation point, or by flat reflectors.展开更多
基金supported by the National Key Research and Development Program of China(2024YFA1209200)the National Natural Science Foundation of China(92250305,92150302,62175213)+1 种基金the New Cornerstone Science Foundation(NCI202216)the Zhejiang Provincial Natural Science Foundation of China(LRG25F050001).
文摘Ultra-confined optical fields are of great importance in fundamental optics and optical technologies.The extreme field confinement in ultra-small nanostructures presents significant challenges in direct near-field characterization.Conventional scanning near-field optical microscopy encounters difficulties in characterizing sub-10-nm confined light fields due to significant disturbances of the optical field caused by the probe.Here,by employing a high spatial-resolved photoemission electron microscopy(PEEM),we succeeded in imaging the ultra-confined near fields of a nanoslit mode in a coupled nanowire pair(CNP)with weak disturbance for the first time and demonstrating a quasi-three-dimensional field distribution of the nanoslit mode.We also show that a PEEM image can identify fabrication defects that are influential to the confined field but are imperceptible to many other means.These results open an opportunity for weak-disturbance characterization of ultra-confined optical near fields,which is an essential step toward future optical devices or technology relying on ultra-confined light.
文摘The compensation method aiming to reduce the irradiation on the user＇s body and to form a weak field area （a dark spot） in an antenna near region is considered. The results of the method development for the use in a narrow frequencies range are given. They show that under realistic conditions the compensation method allows reducing the irradiation power by a factor of 3-4 and more. The pattern changes are predictable and small, if the points of antennas placement are selected correctly. The dark spot necessity near the transmitter is not limited by mobile communication. A man often uses a low-power radio station, which is placed nearby in a vehicle, and it is necessary to protect from irradiation not only user but also other passengers. In the paper, it is shown that broadband field compensation can be achieved in various structures where the needed anti-phase fields are created either by identical antennas or by radiators located at equal distance from the compensation point, or by flat reflectors.
