Boer, GerbenMerenda, FabriceDelacretaz, GuySalathe, Rene2015-09-222015-09-222015-09-222007https://infoscience.epfl.ch/handle/20.500.14299/118454Apparatus for forming a single or a plurality of threedimensional optical traps, the apparatus comprising: a. A collimated light source that is directed onto an array of focalizing refractive or diffractive elements providing a single or a plurality of focal areas, and b. An array of reflective elements, placed opposite to the said focalizing elements described in a), which reflect back the light into the said focal area. The invention also relates to a method for using this apparatus.patentAT521007EP1934645US7759635US2009190221EP1934645WO200704298937698082