Tailoring the waveshape of optical unipolar pulses in a multi-level resonant medium

TL;DR

This paper shows how to control and shape optical unipolar pulses by interacting with a multi-level resonant medium using half-cycle pulses, enabling tailored pulse profiles.

Contribution

It introduces a method to tune the waveform of optical unipolar pulses through coherent control of a multi-level medium with half-cycle pulses, including the approximation by a two-level model.

Findings

Able to produce unipolar pulses with rectangular or triangular profiles.

Efficiently steer medium polarization despite ultrabroad spectrum.

Two-level model approximates medium response below certain pulse amplitudes.

Abstract

We theoretically demonstrate the possibility to tune the temporal waveform of optical unipolar pulses upon their coherent interaction with a multi-level resonant medium. This is achieved through the coherent control of the response of a multi-level resonant medium by means of half-cycle unipolar pulses. We show that despite the ultrabroad spectrum of half-cycle pulses one can efficiently steer the induced medium polarization through the proper choice of the parameters of the excitation pulses. As the result, producing of unipolar optical pulses of varying profile, like rectangular or triangular ones, from an extended layer of a multi-layer medium was obtained when excited by a pair of half-cycle pulses. Besides, we find out that the response of a multi-level medium for the amplitude of the driving pulses below a certain threshold can be quantitatively well approximated by the two-level model.