Self-dual singularity through lasing and antilasing in thin elastic plates

We present here how a coherent perfect absorber-laser (CPAL) enabled by parity-time ($\mathcal{PT}$)-symmetry breaking may be exploited to build monochromatic amplifying devices for flexural waves. The fourth order partial differential equation governing the propagation of waves leads four transfer matrices, and this results in physical properties $\mathcal{PT}$-symmetry specific elastic plate systems. thus demonstrate possibility using CPAL such systems we argue concept detect extremely small-scale vibration perturbations with important outcomes surface science (imaging nanometer vibration) geophysics (improving seismic sensors like velocimeters). device can also generate finite signals very low exciting intensities. system alternatively used as absorber energy tailoring left right incident wave harvesting applications.