A comparative study of three techniques for the fabrication of V₂O₅ thin film saturable absorbers for fiber laser

Abstract A Q-switched fiber laser's stability is crucial for real-world applications. This paper presents methods for enhancing the stability of Q-switched fiber lasers and a thorough measurement procedure. Saturable absorbers (SAs) for Q-switching in an erbium-doped fiber laser (EDFL) were fabricated using V 2 O 5 via the solution method (SM), pulsed laser deposition (PLD), and a mesh powder approach. The resulting thin-film–based SAs were characterized using Raman spectroscopy, photoluminescence (PL), and scanning electron microscopy (SEM). Following that, the V₂O 5 thin films were successfully integrated into the EDFL’s ring cavity to demonstrate stable Q-switched laser operation. Three saturable absorbers (SAs) prepared by different methods were used to assess the output characteristics of the erbium-doped fiber laser (EDFL), and a thorough comparison of their results is provided. The PLD-grown thin-film SA demonstrated the best performance, with a peak power of 14.83 mW, a pulse energy of 100 nJ, and a pulse duration of 5.3 µs. Furthermore, it is discussed that conventional methods for assessing the stability of fiber lasers are necessary but not sufficient to provide a comprehensive evaluation. Therefore, a more complete methodology for stability measurement is proposed and demonstrated. The stability analysis of the laser pulses revealed that the PLD-fabricated SA provided superior performance and stability compared to the SAs prepared using the other two techniques.