Simultaneous Realization of Coherent Perfect Absorber and Laser by Zero-Index Media with both Gain and Loss

Abstract

We investigate a unique type of zero-index medium with both gain and loss (ZIMGL), whose effective permittivity and permeability are purely imaginary and of opposite signs. We show analytically that, by using a slab of ZIM-GL with equal magnitude of loss and gain, coherent perfect absorber (CPA) and laser, i.e. the socalled CPA-laser, can be achieved simultaneously. CPA-laser has been found previously in parity-time (PT) symmetric systems. However, the underlying physics in a PT-symmetric system is distinct from that in a ZIM-GL. By designing a photonic crystal (PC) composed of core-shell rods, with loss and gain distributed in either the core or the shell, we have realized such a ZIM-GL. The CPA-laser functionality of such a PC is also confirmed in our numerical simulations. Our work provides a different approach for simultaneous realization of CPA and laser besides PTsymmetric systems.

20 pages, 5 figures

References in corpus (4)

• Coherent Perfect Absorbers: Time-reversed Lasers
• PT-symmetry breaking and laser-absorber modes in optical scattering systems
• Do Linear Dispersions of Classical Waves Mean Dirac Cones?
• A unified theory for perfect absorption in ultra-thin absorptive films with constant tangential electric or magnetic fields

Cited by in corpus (4)

• Exceptional points and spectral singularities in active epsilon-near-zero plasmonic waveguides
• Contrasting Spectral Signatures and Sensitivities of CPA-Lasing in a $\mathcal{P}\mathcal{T}$-Symmetric Periodic Structure
• Coherent perfect absorber and laser in purely imaginary conjugate metamaterials
• Negative refraction based on purely imaginary conjugate metamaterials