. In addition, we also pick
up the laser spot and move it within the positions of
the three points to determine the scan plane. And then
the range is set as 360 mP×360 mP, scan
points as 60×60 and the vibration frequency is
932.8 kHz, which is the same as the resonance
frequency. Furthermore, the center of the scan range
must coincide with the center of the membrane.
So, the real-time vibration state of the membrane can
be obtained and Fig. 7 shows the multi-point
fixed-frequency vibration characteristics at the
determined frequency