Coherent perfect absorber and laser for nonlinear waves in optical waveguide arrays

Area of Science:

• Nonlinear optics
• Waveguide optics
• Quantum mechanics

Background:

• Non-Hermitian potentials are crucial in various physics domains.
• Optical waveguides offer a platform for studying wave phenomena.
• Controlling wave behavior with localized potentials is an active research area.

Purpose of the Study:

• To investigate the dual behavior of localized non-Hermitian potentials as coherent perfect absorbers or lasers.
• To demonstrate this effect in an array of optical waveguides.
• To generalize the findings to more complex waveguide configurations.

Main Methods:

• Theoretical analysis of nonlinear wave propagation in optical waveguide arrays.
• Modeling localized non-Hermitian potentials.
• Numerical simulations of wave dynamics.

Main Results:

• A localized non-Hermitian potential can function as either a coherent perfect absorber or a laser for nonlinear waves.
• The effect is demonstrated in an optical waveguide array with an active or absorbing central waveguide.
• Different characteristics for left and right arrays are supported, and the concept extends to 2D arrays with embedded subarrays.

Conclusions:

• Localized non-Hermitian potentials provide a versatile tool for controlling nonlinear waves.
• Optical waveguide arrays are suitable systems for realizing these effects.
• The findings have implications for designing advanced optical devices and controlling wave phenomena.