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Updated: May 25, 2026
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Trapping of Micro Particles in Nanoplasmonic Optical Lattice
Published on: September 5, 2017
Optically trapped gold nanoparticle enables listening at the microscale.
Alexander Ohlinger1, Andras Deak, Andrey A Lutich
1Photonics and Optoelectronics Group, Physics Department and CeNS, Ludwig-Maximilians-Universität München, Amalienstraße 54, 80799 Munich, Germany.
Physical Review Letters
|February 7, 2012
Summary
Researchers developed a highly sensitive "nanoear" using optical tweezers to detect faint sound waves in liquids. This breakthrough allows for unprecedented sensitivity in acoustic detection, opening new avenues for microscopic exploration.
Area of Science:
- Physics
- Acoustics
- Nanotechnology
Background:
- Optical tweezers are established tools for manipulating microscopic objects.
- Detecting low-intensity sound waves in liquid media presents significant challenges.
Purpose of the Study:
- To develop a novel ultrasensitive method for detecting sound waves in liquids.
- To demonstrate the capability of optical tweezers for acoustic detection.
Main Methods:
- Utilizing optical tweezers to confine a single gold nanoparticle in a 3D optical trap.
- Employing precise position tracking of the nanoparticle to detect acoustic vibrations.
- Analyzing the nanoparticle's motion in the frequency domain to achieve high sensitivity.
Main Results:
- Ultrasensitive detection of sound waves achieved at sound power levels as low as -60 dB.
- Observed a kinetic energy increase of approximately 90 μeV in the nanoparticle due to acoustic vibrations.
- Demonstrated unprecedented sensitivity through frequency domain analysis of nanoparticle motion.
Conclusions:
- The developed "nanoear" concept offers a highly sensitive method for acoustic detection in liquids.
- This technique enables exploration of biological microorganisms and micromechanical systems previously inaccessible to other microscopy methods.
- The findings pave the way for new applications in sensitive acoustic sensing and microscopic imaging.
