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.　(c)　2025　Optica　Publishing　Group　under　the　terms　of　the　Optica　Open　Access　Publishing　Agreement