The　orthogonality　among　optical　beams　with　different　orbital　angular　momentum　(OAM)　modes　presents　a　new　perspective　as　independent　data-carrying　channels　for　multiplexing　and　demultiplexing.　In　particular,　the　theoretically　infinite　topological　charge　of　OAM　beam　promises　the　unbounded　capacity　in　communication　systems.　As　a　key　part　for　the　advancement　of　OAM　technologies,　OAM　source　has　attracted　considerable　interest　and　experienced　a　rapid　development.　Nevertheless,　conventional　approaches　to　create　OAM　modes　mainly　rely　on　the　use　of　bulky　optical　devices　and　external　laser　source,　preventing　their　implementation　into　a　miniaturized　system.　As　a　contrast,　on-chip　generation　of　OAM　beams　with　a　built-in　source　stands　out　with　several　advantages,　including　small　footprint,　compactness,　portability,　and　high-power　efficiency.　In　this　work,　a　versatile　approach　to　directly　produce　OAM　modes　with　on-demand　characteristics　on　a　chip　is　demonstrated.　Featuring　the　judicious　combination　of　the　emerging　dielectric　metasurface　with　the　standard　vertical　cavity　surface-emitting　laser　(VCSEL)　platform,　the　approach　represents　a　feasible　solution　to　the　wide　implementation　of　wafer-level　OAM　emitters　for　optoelectronic　integrations.　Prototype　laser　chips　for　the　generation　of　both　individual　OAM　beam　and　OAM　array　with　novel　functionalites,　such　as　controllable　directionality　and　spatially　varying　topological　charge　and　distribution,　are　systematically　presented.