Indonesian Journal of Electrical Engineering and Computer Science Vol. 32, No. 1, October 2023, pp. 269~275 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v32.i1.pp269-275  269 Journal homepage: http://ijeecs.iaescore.com Passive mode locking erbium-doped fiber laser using V2O5 polyethylene glycol saturable absorber Mohamad Faizal Baharom 1 , Mohd Fauzi Ab Rahman 2 , Anas Abdul Latiff 3 , Aminah Ahmad 2 , Mohd Hafiz Jali 1 , Sulaiman Wadi Harun 4 1 Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia 2 Faculty of Electrical and Electronic Engineering Technology, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia 3 Faculty of Electronic and Computer Engineering, Universiti Teknikal Malaysia Melaka, Durian Tunggal, Malaysia 4 Department of Electrical Engineering, University of Malaya, Kuala Lumpur, Malaysia Article Info ABSTRACT Article history: Received May 19, 2022 Revised Jul 4, 2023 Accepted Jul 8, 2023 An ultrashort pulse erbium-doped fiber laser (EDFL) in anomalous group delay dispersion (GDD) has been proven to produce a soliton wave production at 1596 nm. The mode-locking operation was generated by employing a vanadium pentoxide-polyethylene glycol (V2O5)-(PEG) film as absorber for all-fiber ring setup. Under anomalous dispersion, the soliton mode-locked laser produced a peak wavelength with 2.7 nm spectral bandwidth and Kelly sidebands. Under this condition, we obtained pulse energy of 210 nJ and pulse width of 1.40 ps. The maximum peak electrical power of 150 kW was calculated at the maximum pump power. These findings shows that the V2O5- PEG film can be a good saturable absorber (SA) device in generating stable mode-locking fiber laser at the 1.55- area. Keywords: Mode-locking Passive technique Polyethylene glycol Pulsed laser Saturable absorber This is an open access article under the CC BY-SA license. Corresponding Author: Mohamad Faizal Baharom Faculty of Electrical Engineering, Universiti Teknikal Malaysia Melaka Durian Tunggal, Melaka, Malaysia Email: mohamad.faizal@utem.edu.my 1. INTRODUCTION Pulsed laser source in light detection and ranging (LiDAR) is one of the recent challenges that should be solved, especially in developing an autonomous vehicle. The commercial 980 nm laser diode (LD) used in the current LiDAR system of the current autonomous vehicle requires further improvement, such as replacing it with a safer laser wavelength. This is important since the system is used to determine the accurate distance for a moving vehicle even at a low speed. The 1.55-micron region is the most suitable wavelength to replace the existing pulsed laser source (980 nm LD), improving the resolution on time by flight. In fact, the fiber laser is recognized as a compact, stable, and practical laser under the field of lasers. High power in wideband operations comes from nonlinear fiber-based technology where ultrashort pulse fiber laser can fully enhance their performances [1]. The pulsed laser has good demand for industrial, military, and medical applications, such as for laser micromachining, surgery, terahertz-wave generation, optical imaging, or super-continuum generation [2]. The ultrahigh resolution of the optical fiber technology using a fiber super-continuum has been proven at various wavelength ranges via the passive and active techniques pulsed lasers [3]. Usually, external sources like electro and acoustic optic modulator are used in active techniques to perform the laser generation. However, it is too complex and bulky [4]. In contrast, a passive saturable absorber (SA) approach can give a more compact, flexible, and simple cavity resilience ability [5]. Semiconductor saturable absorber mirror (SESAM) has been reported to be quite expensive and requires post-growth ion in a demonstration [6]–[10].