From Ultrasound Time-Reversal Mirrors to Matrix Imaging
Can we make a wave revive its past life? The development of ‘time-reversal mirrors’ for different types of waves — ultrasound, microwave and visible light — has made it possible to exploit time reversibility. Such devices bounce waves back and forth with a target like a game of tennis, with the waves becoming more focused over time. These instruments offer original solutions for imaging complex disordered environments.