Fig. 8: Effect of frequency and ultrasound pressure.
From: Ultrasonically sculpted virtual relay lens for in situ microimaging
a Comparison between the ultrasonically sculpted refractive index profiles at f1 = 832 kHz, for a peak pressure of 4.32 MPa (blue line) and at f2 = 1140 kHz, for a peak pressure of 2.25 MPa (orange line). b, c Optical ray tracing simulations of light propagating through the two media modulated by the refractive index profiles shown in a. In both cases, the focal distance inside the medium is ~30 mm. For the higher frequency ultrasonic waves (at f2 = 1140 kHz), the width of the central high refractive index region is smaller compared to the lower frequency ultrasonic waves (at f2 = 832 kHz) and therefore, with a lower peak pressure, light can be focused at the same plane
