{"title":"Air Mass Filters","description":"\u003csection class=\"two\"\u003e\u003cdiv\u003e\n\u003cp class=\"eyebrow\"\u003eSOLAR SIMULATION\u003c\/p\u003e\n\u003ch2\u003eThe optical link\u003cbr\u003ein solar simulation.\u003c\/h2\u003e\n\u003cp\u003eA solar simulator recreates selected characteristics of sunlight for controlled testing. Air Mass filters shape the source spectrum toward the chosen solar reference.\u003c\/p\u003e\n\u003cp\u003eKUPO provides optical support for solar simulator equipment, with OEM filter research, development and custom design for different light sources, optical layouts and testing requirements.\u003c\/p\u003e\n\u003ca class=\"button\" href=\"#oem\"\u003eExplore OEM development →\u003c\/a\u003e\n\u003c\/div\u003e\n\u003cfigure\u003e\u003cimg style=\"width:100%\" src=\"https:\/\/kupooptics.com\/cdn\/shop\/t\/6\/assets\/optics-582e36ebda-am-optic-concept.png\" alt=\"Air Mass optical filter concept illustration\" width=\"1536\" height=\"1024\"\u003e\u003cfigcaption\u003eOptical concept illustration\u003c\/figcaption\u003e\u003c\/figure\u003e\u003c\/section\u003e\n\u003csection\u003e\u003cp class=\"eyebrow\"\u003eUNDERSTANDING AIR MASS\u003c\/p\u003e\n\u003ch2\u003eOne sun.\u003cbr\u003eDifferent spectral references.\u003c\/h2\u003e\n\u003cp class=\"lead\"\u003eAir mass describes the relative path sunlight travels through the atmosphere. Absorption and scattering change its spectral distribution before it reaches the ground.\u003c\/p\u003e\n\u003cdiv class=\"two am-reference-cards\"\u003e\n\u003carticle\u003e\u003cp class=\"eyebrow\"\u003eBEYOND THE ATMOSPHERE\u003c\/p\u003e\n\u003ch3\u003eAM0\u003c\/h3\u003e\n\u003cp\u003eA reference for sunlight outside Earth’s atmosphere, before atmospheric filtering.\u003c\/p\u003e\n\u003cp\u003eA spectral target for space solar-cell research and evaluation of photovoltaic devices intended for extraterrestrial conditions.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003cp class=\"eyebrow\"\u003eTERRESTRIAL SOLAR TESTING\u003c\/p\u003e\n\u003ch3\u003eAM1.5G\u003c\/h3\u003e\n\u003cp\u003eA terrestrial reference with an air mass of 1.5. The “G” means global irradiance, including direct and diffuse light on the reference tilted surface.\u003c\/p\u003e\n\u003cp\u003eA widely used spectral target for evaluating solar cells and photovoltaic devices intended for operation on Earth.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003cp class=\"caption\"\u003eAM0 and AM1.5G describe reference solar spectra, rather than a universal filter shape or a single wavelength.\u003c\/p\u003e\u003c\/section\u003e\n\u003csection\u003e\u003cp class=\"eyebrow\"\u003eWHY THE FILTER MATTERS\u003c\/p\u003e\n\u003ch2\u003eShape the spectrum.\u003cbr\u003eSupport the measurement.\u003c\/h2\u003e\n\u003cdiv class=\"two\"\u003e\n\u003carticle\u003e\u003ch3\u003eBalance the source output.\u003c\/h3\u003e\n\u003cp\u003eThe lamp or light engine has its own spectral distribution. A filter selectively attenuates wavelengths to help bring that output closer to the required reference.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eDesign for the complete system.\u003c\/h3\u003e\n\u003cp\u003eThe resulting spectrum depends on the source, filter, other optics and measurement plane. A passive filter cannot add wavelengths missing from the source; spectral matching is verified in the assembled simulator.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"am-process\"\u003e\n\u003cspan\u003eSource spectrum\u003c\/span\u003e\u003cb\u003e→\u003c\/b\u003e\u003cspan\u003eCustom Air Mass filter\u003c\/span\u003e\u003cb\u003e→\u003c\/b\u003e\u003cspan\u003eSystem optics\u003c\/span\u003e\u003cb\u003e→\u003c\/b\u003e\u003cspan\u003eMeasured output\u003c\/span\u003e\n\u003c\/div\u003e\u003c\/section\u003e\n\u003csection\u003e\u003cp class=\"eyebrow\"\u003eAPPLICATIONS\u003c\/p\u003e\n\u003ch2\u003eOptics for solar research\u003cbr\u003eand equipment development.\u003c\/h2\u003e\n\u003cdiv class=\"two\"\u003e\n\u003carticle\u003e\u003ch3\u003ePhotovoltaic evaluation\u003c\/h3\u003e\n\u003cp\u003eSupport controlled illumination for solar-cell and photovoltaic-device characterization against the selected spectral reference.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eSpace photovoltaics\u003c\/h3\u003e\n\u003cp\u003eDevelop optical filtering around AM0 targets for space-oriented solar-cell research and evaluation.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eSolar simulator OEMs\u003c\/h3\u003e\n\u003cp\u003eIntegrate a source-specific filter into new equipment platforms, optical modules or simulator upgrades.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eLaboratory development\u003c\/h3\u003e\n\u003cp\u003eInvestigate spectral-response requirements and refine the optical design through prototype testing.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\u003c\/section\u003e\n\u003csection id=\"standards\"\u003e\u003cp class=\"eyebrow\"\u003eSTANDARDS \/ KNOW THE DIFFERENCE\u003c\/p\u003e\n\u003ch2\u003eA reference spectrum.\u003cbr\u003eA system classification.\u003c\/h2\u003e\n\u003cp class=\"lead\"\u003eSome standards define the sunlight to reproduce. Others define how to evaluate the complete solar simulator. Knowing the difference helps turn a project brief into a useful optical specification.\u003c\/p\u003e\n\u003cdiv class=\"table-scroll\"\u003e\u003ctable\u003e\n\u003ccaption\u003eSolar simulation standards guide · reviewed 17 September 2026\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eReference\u003c\/th\u003e\n\u003cth\u003eWhat it addresses\u003c\/th\u003e\n\u003cth\u003eWhat it means for your project\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eIEC 60904-9:2020\u003c\/th\u003e\n\u003ctd\u003eClassification of solar simulators for terrestrial photovoltaic testing.\u003c\/td\u003e\n\u003ctd\u003eEvaluates spectral match, spatial non-uniformity and temporal instability. Includes A+, A, B and C classifications.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eIEC 60904-3:2019\u003c\/th\u003e\n\u003ctd\u003ePV measurement principles and terrestrial reference spectral irradiance.\u003c\/td\u003e\n\u003ctd\u003eDefines the reference light distribution used in the relevant PV measurement framework.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eIEC 60904-7:2019\u003c\/th\u003e\n\u003ctd\u003eCorrection of spectral mismatch in PV testing.\u003c\/td\u003e\n\u003ctd\u003eAddresses differences between the test spectrum, reference spectrum and device spectral responses.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eASTM E927-19(2025)\u003c\/th\u003e\n\u003ctd\u003eSolar simulator classification for electrical performance testing of photovoltaic devices.\u003c\/td\u003e\n\u003ctd\u003eEvaluates the simulator’s spectral, spatial and temporal characteristics under the applicable test conditions.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eASTM G173-23\u003c\/th\u003e\n\u003ctd\u003eTerrestrial reference solar spectra: direct normal and global irradiance on a 37° tilted surface.\u003c\/td\u003e\n\u003ctd\u003eThe global reference supports AM1.5G spectral-target discussions. It is a reference spectrum, not an equipment certification.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eASTM E490-22\u003c\/th\u003e\n\u003ctd\u003eZero-air-mass reference solar spectral irradiance.\u003c\/td\u003e\n\u003ctd\u003eProvides an AM0 reference for applications such as space-oriented photovoltaic testing.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eJapan: JIS C 8904-9:2017\u003cbr\u003e\u003csmall\u003eHistorical \/ withdrawn\u003c\/small\u003e\n\u003c\/th\u003e\n\u003ctd\u003eFormer Japanese solar simulator performance requirements, following earlier references including JIS C 8912:1998.\u003c\/td\u003e\n\u003ctd\u003eWithdrawn on 20 December 2023. The Japanese Standards Association states that IEC 60904-9:2020 can be referenced without additional Japan-specific requirements. Identify the applicable edition in Japanese procurement documents.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cp class=\"caption\"\u003eThis is an original practical overview, not a reproduction of the standards. Confirm the specified edition, reference spectrum, wavelength intervals and measurement conditions for each project. Terrestrial classification requirements must not automatically be applied to an AM0 space-testing setup.\u003c\/p\u003e\u003c\/section\u003e\n\u003csection id=\"aaa\"\u003e\u003cp class=\"eyebrow\"\u003eKUPO OPTICAL SUPPORT\u003c\/p\u003e\n\u003ch2\u003eDesigned to support\u003cbr\u003eAAA-class solar simulators.\u003c\/h2\u003e\n\u003cp class=\"lead\"\u003eKUPO develops source-specific Air Mass filters with spectral-matching capability of ±5% per agreed wavelength band for qualified equipment configurations. Our OEM development supports equipment teams working toward AAA-class simulator performance.\u003c\/p\u003e\n\u003cdiv class=\"two\"\u003e\n\u003carticle\u003e\u003ch3\u003eWhat does AAA describe?\u003c\/h3\u003e\n\u003cp\u003eAAA is commonly used to indicate Class A performance in three separate system characteristics. The applicable standard, edition, test area and measurement conditions must accompany the rating.\u003c\/p\u003e\n\u003cul class=\"list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpectral match:\u003c\/strong\u003e how the output distribution compares with the reference.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpatial uniformity:\u003c\/strong\u003e how evenly the test area is illuminated.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemporal stability:\u003c\/strong\u003e how consistently the irradiance is maintained during measurement.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eWhere does the Air Mass filter contribute?\u003c\/h3\u003e\n\u003cp\u003eThe filter shapes the spectrum and supports the spectral-matching requirement. Source control, beam-forming optics and the complete equipment design also determine uniformity and stability.\u003c\/p\u003e\n\u003cp\u003eAAA is a simulator-level result verified on the assembled system, not a stand-alone filter certification. IEC 60904-9:2020 also defines A+; an AAA description should not be presented as the highest category in that edition.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"am-band-note\"\u003e\n\u003cp class=\"eyebrow\"\u003eUNDERSTANDING ±5%\u003c\/p\u003e\n\u003ch3\u003eCompare the energy share in each band.\u003c\/h3\u003e\n\u003cp\u003eFor a band-integrated relative matching specification, compare each band’s share of the measured total with its share of the reference total over the same agreed wavelength interval.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBand match = measured band fraction ÷ reference band fraction\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA ±5% relative tolerance means a band-match ratio of 0.95–1.05. For example, if a reference band contains 20% of the interval’s energy, a matching band fraction is 19–21%. This is an explanatory example, not a KUPO test result.\u003c\/p\u003e\n\u003cp\u003eIt does not mean ±5 percentage points, ±5% at every individual wavelength, or that the complete simulator has passed all three classification tests. The source, band definitions, normalization interval, angle and test-plane conditions are agreed during project review.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e\n\u003csection id=\"who-we-support\"\u003e\u003cp class=\"eyebrow\"\u003eWHO WE SUPPORT\u003c\/p\u003e\n\u003ch2\u003eFor the teams turning\u003cbr\u003esolar light into reliable data.\u003c\/h2\u003e\n\u003cdiv class=\"two\"\u003e\n\u003carticle\u003e\u003ch3\u003eSolar simulator manufacturers\u003c\/h3\u003e\n\u003cp\u003eOEM developers integrating Air Mass optics into new platforms, source upgrades and application-specific simulator designs.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eUniversity photovoltaic laboratories\u003c\/h3\u003e\n\u003cp\u003eElectrical engineering, materials science, applied physics and renewable-energy groups studying silicon, thin-film, perovskite and tandem solar cells.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eNational research \u0026amp; metrology laboratories\u003c\/h3\u003e\n\u003cp\u003eTeams developing reference measurements, calibration methods and spectral-mismatch studies. The filter supports the optical system; calibration traceability remains a separate laboratory responsibility.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003ePV manufacturers \u0026amp; test laboratories\u003c\/h3\u003e\n\u003cp\u003eCell and module R\u0026amp;D, process development and performance-evaluation teams that need reproducible test illumination and a defined spectral target.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eSpace photovoltaic \u0026amp; aerospace teams\u003c\/h3\u003e\n\u003cp\u003eResearch groups evaluating solar cells and materials under an agreed AM0 spectral reference, with optics developed for the intended test setup.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003ch3\u003eMaterials \u0026amp; photochemistry research\u003c\/h3\u003e\n\u003cp\u003eUniversity and industrial laboratories exploring solar-driven reactions or material response. Spectrum, irradiance and exposure must suit the experiment; a PV simulator classification alone does not validate an aging or photochemical test.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003cp class=\"caption\"\u003eApplication examples describe teams that may benefit from Air Mass optical development; they are not a list of KUPO customers or institutional endorsements.\u003c\/p\u003e\u003c\/section\u003e\n\u003csection class=\"am-band-note\"\u003e\u003cp class=\"eyebrow\"\u003eWHY WORK WITH KUPO\u003c\/p\u003e\n\u003ch2\u003eOne optical partner,\u003cbr\u003efrom target to integration.\u003c\/h2\u003e\n\u003cp\u003eBring your source spectrum and equipment requirements to a team combining thin-film coating, in-house manufacturing and spectral inspection. We can develop the filter around your optical and mechanical constraints, evaluate prototypes and refine the design for OEM integration.\u003c\/p\u003e\n\u003cp\u003eWhether you are building a university test bench or a simulator product line, start with your Air Mass reference, wavelength bands, source, beam geometry and required spectral match. We will help translate them into a measurable filter-development brief.\u003c\/p\u003e\n\u003ca class=\"button\" href=\"\/collections\/all?view=optics-request-solar\"\u003eDiscuss your Air Mass optical requirements →\u003c\/a\u003e\u003c\/section\u003e\n\u003csection id=\"oem\"\u003e\u003cp class=\"eyebrow\"\u003eOEM \/ CUSTOM RESEARCH \u0026amp; DEVELOPMENT\u003c\/p\u003e\n\u003ch2\u003eDeveloped around\u003cbr\u003eyour equipment.\u003c\/h2\u003e\n\u003cp class=\"lead\"\u003eFrom a new solar simulator platform to a specific source-and-optics combination, KUPO can collaborate on custom Air Mass filter development.\u003c\/p\u003e\n\u003cdiv class=\"steps\"\u003e\n\u003carticle\u003e\u003cp class=\"eyebrow\"\u003e01\u003c\/p\u003e\n\u003ch3\u003eDefine the target\u003c\/h3\u003e\n\u003cp\u003eShare the Air Mass reference, wavelength interval, source spectrum and equipment objectives.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003cp class=\"eyebrow\"\u003e02\u003c\/p\u003e\n\u003ch3\u003eDesign the optic\u003c\/h3\u003e\n\u003cp\u003eReview spectral shaping, substrate, coating, working angle, dimensions and thermal conditions.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003cp class=\"eyebrow\"\u003e03\u003c\/p\u003e\n\u003ch3\u003eEvaluate prototypes\u003c\/h3\u003e\n\u003cp\u003eMeasure the filter and assess the spectral result in the intended optical system.\u003c\/p\u003e\u003c\/article\u003e\u003carticle\u003e\u003cp class=\"eyebrow\"\u003e04\u003c\/p\u003e\n\u003ch3\u003eRefine for integration\u003c\/h3\u003e\n\u003cp\u003eAgree the final specification and mechanical interface, then plan OEM production requirements.\u003c\/p\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003ca class=\"button\" href=\"\/collections\/all?view=optics-request-solar\"\u003eDiscuss your solar simulator project →\u003c\/a\u003e\u003c\/section\u003e","products":[],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0818\/8651\/1359\/collections\/optics-582e36ebda-am-optic-concept.png?v=1790246274","url":"https:\/\/kupooptics.com\/collections\/air-mass.oembed","provider":"KUPO Optics","version":"1.0","type":"link"}