Characterization of surface acoustic waves by stroboscopic white-light interferometry

Abstract

We present phase-sensitive absolute amplitude measurements of surface acoustic wave fields obtained using a stroboscopic white-light interferometer. The data analysis makes use of the high resolution available in the measured interferometric phase data, enabling the characterization of the out-of-plane surface vibration fields in electrically excited microstructures with better than 100 pm amplitude resolution. The setup uses a supercontinuum light source with tailored spectral properties for obtaining the high amplitude resolution. The duration of the light pulses is less than 300 ps to allow the detection of high frequencies. These capabilities enabled a detailed measurement of the focusing of surface acoustic waves by an annular interdigital transducer structure operating at 74 MHz, featuring a maximum vibration amplitude of 3 nm.

Recent Advances in Spatial Self‐Phase Modulation with 2D Materials and its Applications

“…White light interference has been widely used for the accurate measurement of microstructures due to its non-contact high sensitivity and large measurement range. [213][214][215] The traditional rainbow is a non-coherent optical phenomenon, which is mainly caused by the different refractive index of water with different Intensity distributions in the case of (h)-(j). Reproduced with permission.…”

Micro Vibration Measurement with Microscopic Speckle Interferometry Based on Orthogonal Phase

“…Optical interferometry has the advantages of non-contact, high accuracy, and direct measurement of micro-vibration, so they have been widely used. Common optical interferometry includes homodyne interferometry [1][2][3][4][5][6], heterodyne interferometry [7][8][9][10][11][12], Sagnac interferometry [13] and stroboscopic white light interferometry [14][15][16][17]. Knuuttila, J. V. et al [3] demonstrated a homodyne scanning Michelson interferometer, which can directly measure the surface acoustic wave in the range of 0.5 MHz to 1 GHz.…”

“…Under the premise of ensuring high accuracy, the maximum measurement is 300 pm. Kokkonen, K. et al [15]…”

Visualization of ultrasonic wave field by stroboscopic polarization selective imaging

“…In order to address this issue, full-field imaging methods based on diffraction and interferometry polarimetry have been developed to visualize variations of the detection optical wave induced by the acoustic waves [12,13]. By combining with a stroboscopic timing scheme, transient surface acoustic waves have been dynamically visualized with photorefractive interferometry [14] and white-light interferometry [15]. Also, Schlieren photography has been utilized to image the dynamic sound pressure in the air [16,17].…”