Herein,　we　present　aN　Er-doped　all-fiber　laser　with　BiVO4　as　the　saturable　absorber　(SA).　To　illustrate　the　nonlinear　optical　response,　a　two-dimensional　model　of　monoclinic　and　its　electronic　structure　was　calculated.　The　nonlinear　absorption　properties　were　evaluated　utilizing　the　Z-scan　technique,　and　a　saturable　absorber　was　fabricated　for　integration　into　a　fiber　laser,　resulting　in　a　stable　Q-switched　output.　At　a　maximum　pump　power　of　600　mW,　the　fiber　laser　achieved　an　average　output　power　of　25.23　mW　and　a　pulse　energy　of　330.76　nJ.　This　research　confirms　that　BiVO4　material　exhibits　outstanding　nonlinear　optical　characteristics,　thereby　broadening　its　scope　of　application　in　the　realm　of　ultrafast　pulsed　fiber　lasers.　©　2025　Optica　Publishing　Group　under　the　terms　of　the　Optica　Open　Access　Publishing　Agreement.