Title: Dynamic near-field optical interaction between oscillating nanomechanical structures

Abstract

Near-field optical techniques exploit light-matter interactions at small length scales for mechanical sensing and actuation of nanomechanical structures. Here, we study the optical interaction between two mechanical oscillators—a plasmonic nanofocusing probe-tip supported by a low frequency cantilever, and a high frequency nanomechanical resonator—and leverage their interaction for local detection of mechanical vibrations. The plasmonic nanofocusing probe provides a confined optical source to enhance the interaction between the two oscillators. Dynamic perturbation of the optical cavity between the probe-tip and the resonator leads to nonlinear modulation of the scattered light intensity at the sum and difference of their frequencies. This double-frequency demodulation scheme is explored to suppress unwanted background and to detect mechanical vibrations with a minimum detectable displacement sensitivity of 0.45 pm/Hz^1/2, which is limited by shot noise and electrical noise. We explore the demodulation scheme for imaging the bending vibration mode shape of the resonator with a lateral spatial resolution of 20 nm. We also demonstrate the time-resolved aspect of the local optical interaction by recording the ring-down vibrations of the resonator at frequencies of up to 129 MHz. Lastly, the near-field optical technique is promising for studying dynamic mechanical processes in individual nanostructures.

Authors:

Ahn, Phillip ^[1]; Chen, Xiang ^[1]; Zhang, Zhen ^[1]; Ford, Matthew ^[1]; Rosenmann, Daniel ^[2]; Jung, II Woong ^[2]; Sun, Cheng ^[1]; Balogun, Oluwaseyi ^[3]

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+ Show Author Affiliations

1. Northwestern Univ., Evanston, IL (United States). Mechanical Engineering Dept.
2. Argonne National Lab., Argonne, IL (United States). Center for Nanoscale Materials.
3. Northwestern Univ., Evanston, IL (United States). Mechanical Engineering and Civil and Environmental Engineering Depts.

Publication Date:

Wed May 27 00:00:00 EDT 2015

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

OSTI Identifier:

1214831

Alternate Identifier(s):

OSTI ID: 1332972

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Scientific Reports

Additional Journal Information:

Journal Volume: 5; Journal ID: ISSN 2045-2322

Publisher:

Nature Publishing Group

Country of Publication:

United States

Language:

English

Subject:

77 NANOSCIENCE AND NANOTECHNOLOGY; scanning probe microscopy; super-resolution microscopy; 36 MATERIALS SCIENCE