A　3D　surface-enhanced　Raman　scattering　(SERS)　sensor　is　realized　on　the　facet　of　an　optical　fiber.　A　SERS　radar　configuration　consisting　of　a　parabolic　mirror　and　a　3D　spherical　SERS　body　is　designed.　The　parabolic　mirror　is　used　to　focus　the　excitation　laser　light　onto　the　surface　of　the　SERS　body,　and　to　collect　and　reflect　the　Raman　scattered　light　back　into　the　optical　fiber.　The　SERS　body＇s　surface　consists　of　microscale　trenches　and　is　covered　with　gold　nanogratings　and　nanoparticles　on　a　thick　gold　film　with　a　thin　SiO2　spacer.　Nanoscale　3D　printing　technology,　thermal　evaporation,　and　UV　laser　pulse　irradiation　are　used　to　fabricate　and　metalize　the　mold　of　the　3D　SERS　radar　confi　guration.　The　performance　of　this　Au-based　SERS　fi　ber　sensor　is　competitive　with　those　of　Ag-based　SERS　fi　ber　sensors　reported　in　the　literature.　It　exhibits　a　detection　limit　of　10(-6)　M　for　crystal　violet　in　ethanol　using　30　mW　of　785　nm　excitation　(off　resonance　with　the　crystal　violet　electronic　absorption)　and　10　s　acquisition　time.　Such　a　3D　scheme　expands　the　design　possibilities　of　SERS　nanostructures　on　the　facets　of　optical　fibers　enormously.