Vertical　Cavity　Surface　Emitting　LaserVCSELarray　has　the　advantages　of　high　integrationhigh　modulation　bandwidthhigh　output　powerfast　response　and　individual　addressingso　it　is　widely　used　in　parallel　optical　interconnection3D　recognition　and　sensinghigh　resolution　printing　and　other　fields.　With　the　development　of　science　and　technologythe　quality　of　laser　array　light　source　is　required　to　be　higher.　For　examplein　order　to　suppress　the　speckle　phenomenon　and　realize　confocal　micro-interference　detection　with　high　spatial　resolution　and　high　contrastthe　VCSEL　array　light　source　is　required　to　have　flat　top　beam　output　with　low　spatial　coherence.　In　the　optical　capture　and　microoperation　of　biological　cellsin　order　to　produce　an　optical　trapping　array　effectthe　beam　of　the　VCSEL　array　needs　to　be　regulated　into　Laguerre-Gaussian　hollow　circular　distribution.　The　beam　distribution　and　spatial　coherence　of　VCSEL　and　its　array　have　attracted　more　and　more　attention.　Similarlyin　free-space　optical　communicationthe　laser　beam　distribution　and　spatial　coherence　are　closely　related　to　the　disturbance　effects　such　as　beam　broadeningspot　drift　and　intensity　scintillation　transmitted　in　a　turbulent　atmospheric　scattering　medium.　It　is　of　great　significance　to　research　the　spatial　coherence　and　light　field　distribution　of　array　light　source　to　optimize　their　transmission　characteristics.　In　this　paperthe　spectrum　of　the　VCSEL　array　is　measured　and　the　light　field　distribution　of　the　VCSEL　array　is　researched.　At　the　threshold　currentthe　VCSEL　array　is　emitted　as　the　fundamental　modeand　the　energy　of　the　fundamental　mode　beam　is　distributed　in　the　center　of　the　luminous　aperture　and　the　light　spot　divergence　degree　is　small.　At　this　timethe　far　field　of　the　array　is　a　circular　light　spot　formed　by　the　superposition　of　the　light　beams　of　each　luminous　unitand　the　light　field　is　Gaussian　distribution.　With　the　increase　of　injection　currentthe　high-order　mode　of　the　VCSEL　array　beam　gradually　appears.　Because　the　energy　of　the　high-order　mode　is　mainly　concentrated　at　the　edge　of　luminous　aperturethe　light　field　of　the　VCSEL　array　is　Laguerre-Gaussian　hollow　circle.　Furthermorethe　experimental　device　of　VCSEL　array　beam　space　transmission　was　built.　The　propagation　characteristics　of　a　standard　coherent　light　source　and　VCSEL　array　beam　with　different　coherence　were　compared　in　the　atmospheric　turbulent　scattering　medium.　The　VCSEL　array　beam　is　collimated　out　through　the　lensafter　the　beam　splitter　through　the　two-hole　interferencethe　interference　fringes　are　recorded　by　Spiricon　SP920s　beam　analyzerand　the　spatial　coherence　of　the　beam　is　obtained　by　calculating　the　contrast　of　the　interference　fringes.　At　the　same　timethe　randomness　and　inhomogeneity　of　atmospheric　turbulence　are　simulated　by　a　scattering　medium.　The　beam　analyzer　is　used　to　record　the　far-field　spot　radius　and　light　intensity　before　and　after　VCSEL　array　beam　transmissionand　the　beam　expansion　rate　and　light　intensity　attenuation　rate　in　the　transmission　process　is　calculated.　Experiments　show　that　compared　with　the　standard　coherent　light　sourcethe　VCSEL　array　beam　has　smaller　spot　diffusion　and　lower　light　intensity　attenuation　when　propagating　in　a　turbulent　atmospheric　scattering　medium.　As　the　spatial　coherence　of　the　VCSEL　array　decreases　from　0.695　to　0.608the　spot　spread　rate　decreases　from　8.6%　to　3.4%and　the　intensity　attenuation　rate　decreases　from　24.9%　to　15%.　VCSEL　array　beams　with　relatively　low　spatial　coherence　show　better　propagation　characteristicswhich　has　important　guiding　significance　for　the　application　of　VCSEL　array　light　source　in　the　fields　of　free　space　radar　detection　and　optical　communication.　©　2022　Chinese　Optical　Society.　All　rights　reserved.