A new scheme for calibrating the direction of vibration of micron lines by strong magnetic field center

[ Instrument Network Instrument Development ] The Xue Fei research team of the Strong Magnetic Field Science Center of the Chinese Academy of Sciences proposed a new scheme for detecting the vibration mode of micro-wire mechanical vibrators using a microlens fiber interferometer. The related results are published in Applied Physics, entitled "Theuring the orientation of the flexural vibrations of a cantilevered microwire with a micro-lens fiber-optic interferometer and Determining the orientation of the flexural modes of a particularly driven microwire cantilever" (Applied Physics) Letters) and Journal of Applied Physics.

Experimental calibration of the vibration direction of rectangular and trapezoidal sections

Mechanical Resonator is a mechanical structure with a specific resonant frequency. It can be found in the ubiquitous nature, from the molecular scale to the galaxy universe. In daily life, mechanical vibrators have also been widely used in construction, watches, musical instruments, biology and other fields. With the advancement of micro-nano processing technology, the size of mechanical vibrators has become smaller and smaller, which has greatly promoted the vigorous development of related fields such as atomic force microscopy and molecular motors. In recent years, mechanical vibrators typified by cantilever beam microwires and nanowires have been used to achieve sensitive detection of small physical quantities such as mass, force, temperature gradient, and the like. Studies have pointed out that the resolution of the cantilever beam vibration mode helps to further improve the sensitivity of detection. Therefore, the detection of the vibration mode of the mechanical vibrator has become an important issue.

The finite element simulation analysis can give a theoretical description of the vibration mode, and the experimental characterization method is mainly the laser Doppler vibrometer. Since only vibration parallel to the incident light can be detected, the scheme needs to assume that the two vibration modes are nearly simple and perpendicular to each other. Recent research suggests that this assumption is not always true, so independent calibration of individual vibration modes makes sense. It has been reported that the four-quadrant detector directly measures a single vibration mode, but the design apparatus is complicated, the optical path adjustment requirements are high, and due to the use of a free optical path, it is not suitable for use in extreme environments such as extremely low temperature and strong magnetic field. A new scheme for detecting the vibration mode of the cantilever beam micro-wire proposed by the strong magnetic field center is to use a self-built microlens fiber interferometer, combined with the scattering effect and interference effect of the interaction between the laser and the microwire, to achieve multiple vibration modes for the microwire. Independent experiments are directly calibrated without introducing any a priori assumptions into their vibration modes.

This research can extend the application of sensitive mass detection based on micro-wire mechanical vibrators and vector torque magnetic detection based on micro-nano mechanical vibrators to extreme environmental conditions such as extremely low temperature and strong magnetic field.

The work received strong support from the National Key Research and Development Program, the National Natural Science Foundation, the Hefei Substance Science and Technology Center Development Fund Major Project and the Hefei Science Center Technology Development Fund of the Chinese Academy of Sciences.

(Original title: A new scheme for realizing the direction of vibration of the micron line by the strong magnetic field center)