# Coherent control of Optical limiting in atomic systems

## TL;DR

This paper investigates how laser fields and magnetic fields can coherently control optical limiting in a four-level atomic system, with potential applications in designing tunable optical limiters.

## Contribution

It introduces a method to coherently control optical limiting using laser intensity, frequency, and magnetic fields in a four-level atomic system, supported by Z-scan validation.

## Key findings

- Laser fields induce and control RSA and OL.
- Magnetic field enhances the OL intensity range.
- OL threshold decreases with increased medium density or length.

## Abstract

Generation and control of the reverse saturable absorption (RSA) and optical limiting (OL) are investigated in a four-level Y-type quantum system. It is demonstrated that the applied laser fields induce the RSA and it can be coherently controlled by either intensity or frequency of the applied laser fields. The effect of the static magnetic field on the induced RSA is studied and we obtain that it has a constructive role in determining the intensity range in which the OL is established in the system. In addition, we find that the OL threshold can be decreased either by increasing the length of the medium or by getting the atomic system denser. Finally, Z-scan technique is presented to confirm our theoretical results. The proposed scheme can be used in designing the coherent optical limiters with controllable threshold and intensity range of OL.