Optical modulation in Er-doped fiber laser delivering dark pulse utilizing side polished fiber coated with Ti3AlC2 as saturable absorber

Abstract

Dark pulse mode-locked Erbium doped fiber laser (EDFL) was demonstrated in this work by employing side polished fiber (SPF) coated with Ti3AlC2 solution using drop casting method. The modulation depth of fabricated SPF coated with Ti3AlC2 solution was characterized at 2.2%. This SPF coated structure allowed the formation of dark mode-locked pulse with improved the birefringence and nonlinearity in EDFL. The dark pulse generated was cubic-quintic nonlinear Schrödinger equation (CQNLSE) dark pulse with center wavelength at 1558.935 nm, repetition rate 1.839 MHz and pulse width 170.2 ns. Pulse stability was examined, revealing a high signal to noise ratio (SNR) of 65.86 dB. This work could serve as a foundation for the development of sustainable industry, innovation and infrastructure.