Researchers employ antennas for angstrom displacement sensing

Schema of the near-field interaction between the antennas and incident light field. Credit: ZANG Tianyang et al.

Optical metrology is of particular significance for it allows measurements of distance or displacement in a noncontact high-precision way.

However, despite of the wide application in longitudinal displacement measurement of interferometric method, such as laser radar, laser ranging and small vibration measurement, lateral displacement perpendicular to the direction of the beam is hard to be detected through conventional methods.

The researchers presented a novel technique based on directional excitation of surface plasmon polaritons (SPPs).

They first excited asymmetric SPPs with a pair of optical slot antennas under the illumination of the focused Hermite-Gaussion (HG) (1,0) mode light. Then, by detecting the SPPs leakage at the back-focal plane of an oil-immersed objective, they sensitively measured the transverse displacement.

Unlike the previous strategy to retrieve the free scattering signals, which remains challenging even when employing a weak measurement technique, the SPPs leakage pattern is spatially separated from the forward scattering of the slot antennas, and thus could be utilized to monitor displacements in the back-focal plane.

The resolution of their system reaches subwavelength level (~0.3 nm).

However, the extreme resolution could be down to angstrom level. It is potentially applicable in superresolution microscopy, semiconductor lithography, and calibration of nanodevices.

Media Contact

Jane FAN Qiong

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

Cooling down solar cells, naturally

Photovoltaics are more efficient when they operate at lower temperatures, which can be achieved in solar farms that space out arrays and use the wind to their advantage. A bright,…

Strongest Arctic cyclone on record led to surprising loss of sea ice

A warming climate is causing a decline in sea ice in the Arctic Ocean, where loss of sea ice has important ecological, economic and climate impacts. On top of this…

Tuberculosis and COVID-19 lung lesions

… revealed by high-resolution three-dimensional imaging. Insights that are not possible with conventional two-dimensional platforms include characterization of obliterated airways in tuberculosis and hemorrhage from ruptured blood vessels in COVID-19…

Partners & Sponsors