Fig. 6: Scanning through the depth of the medium.
From: Ultrasonically sculpted virtual relay lens for in situ microimaging
a Experimental images of the axial profiles of the optical beam inside the ultrasonic cavity for three different input voltages at the resonant frequency fres = 832 kHz, showing the axial foci at the top, in the middle, and at the bottom (indicated by red arrows). Raw data and fitted curves showing the intensity profiles of light for the three images in Fig. 5a when the transducer is off and when it is on, driven at b 34 V, c 43.3 V, and d 52.3 V. The maximum intensities of the fitted profiles are indicated by red arrows. e Comparison between the simulated axial locations of the foci and the experimental results. Changing the input drive voltage enables axial scanning: f at V1 = 40.3 V, the target is out of focus, g at V2 = 46.3 V, the image is clearly resolved, and h a further increase in voltage to V3 = 52.3 V results in a newly out-of-focus image
