It is a big challenge for lidar to detect soft targets over long distances in the atmosphere due to the low reflection of soft targets and the strong atmospheric attenuation. In this paper, we propose an all-day lidar system based on the 4 pixel array superconducting nanowire single-photon detectors. This significantly improves the detection efficiency of the aerosol and other targets by utilizing the advantages of high sensitivity, low dark count rate, wide dynamic range and photon number resolution. The system detects both soft targets and hard targets 100 km away in the atmosphere. In experiments, based on the photon-number resolving detection method, the lidar detects and distinguishes soft and hard targets simultaneously 50 km away during the day. Furthermore, the system obtains the wind field information in the atmosphere by monitoring clouds at a distance exceeding 86 km. The detection results indicate that the system is promising for applications as a long distance all-day lidar.
Electron beam lithography uses an accelerated electron
beam to
fabricate patterning on an electron-beam-sensitive resist but requires
complex dry etching or lift-off processes to transfer the pattern
to the substrate or film on the substrate. In this study, etching-free
electron beam lithography is developed to directly write a pattern
of various materials in all-water processes, achieving the desired
semiconductor nanopatterns on a silicon wafer. Introduced sugars are
copolymerized with metal ions-coordinated polyethylenimine under the
action of electron beams. The all-water process and thermal treatment
result in nanomaterials with satisfactory electronic properties, indicating
that diverse on-chip semiconductors (e.g., metal oxides, sulfides,
and nitrides) can be directly printed on-chip by an aqueous solution
system. As a demonstration, zinc oxide patterns can be achieved with
a line width of 18 nm and a mobility of 3.94 cm2 V–1 s–1. This etching-free electron
beam lithography strategy provides an efficient alternative for micro/nanofabrication
and chip manufacturing.
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