# Trajectory manipulation of an Airy pulse near zero dispersion wavelength under free carrier generated linear potential

## TL;DR

This paper explores how a free carrier induced linear potential in a Si waveguide near zero GVD wavelength can manipulate Airy pulse trajectories, enabling spectral shifts and trajectory control for pulse reshaping applications.

## Contribution

It introduces a mathematical model for Airy pulse dynamics under a free carrier generated linear potential, including solutions with non-zero third order dispersion and pulse flipping behavior.

## Key findings

- Linear potential causes spectral shifts of Airy pulses.
- Trajectory deviations can be tailored by potential strength.
- Pulse flipping occurs at specific potential strengths, with revivals beyond flipping.

## Abstract

We investigate the dynamics of an Airy pulse that experiences free carrier generated optical linear potential in the vicinity of zero group velocity dispersion (GVD) wavelength inside a Si based waveguide. The optically induced potential can be realized by an inhomogeneous medium which possesses a time dependent refractive index. We propose a pump-probe scheme in Si-based waveguide where a strong continuous wave (CW) pump excites free carriers that leads to a linear potential through a time dependent refractive index change which is experienced by the finite energy Airy pulse (FEAP) (probe). The linear potential significantly manipulate the dynamics of a FEAP and leads to a monotonous spectral shift. We mathematically model the dynamics of the Airy pulse using linear dispersion equation containing an optical potential term and establish the general solution of the pulse for non-vanishing third order dispersion (TOD). We derive the expression of the trajectory of FEAP which deviates significantly from its usual ballistic nature and can be tailored with the strength of the linear potential. For positive TOD, the propagating Airy pulse experiences a singularity and flips in time domain. We theoretically derive that for a specific potential strength the flipping region is squeezed to a point and revives thereafter. We propose an exact analytical solution beyond flipping region for this specific case. Our theoretical analysis corroborates well with the numerical results. The present study may be useful in applications related to pulse reshaping and trajectory manipulation