P T -Symmetry Breaking and Laser-Absorber Modes in Optical Scattering Systems

Using a scattering matrix formalism, we derive the general scattering properties of optical structures that are symmetric under a combination of parity and time reversal (PT). We demonstrate the existence of a transition between PT-symmetric scattering eigenstates, which are norm preserving, and symmetry-broken pairs of eigenstates exhibiting net amplification and loss. The system proposed by Longhi [Phys. Rev. A 82, 031801 (2010).], which can act simultaneously as a laser and coherent perfect absorber, occurs at discrete points in the broken-symmetry phase, when a pole and zero of the S matrix coincide.

• NS
  National Science Foundation

  Awards: 0520495, 0908437, DMR-0908437
• YU
  Yale University
• MR
  Materials Research Science and Engineering Center, Harvard University
• DO
  Division of Materials Research