on the glass side of the window often the customer supplies their own glass substrate as well the most common geometries of the lenslets are circular square and hexagonal and the most common geometry of the array itself is square the aperture of each lenslet can be as small as approximately 15 microns or less and the focal length can be as short as approximately 30 microns or less microlens arrays containing lenslets of various apertures and focal lengths are commercially designed and fabricated micro baffles can be sets of transparent holes designed and fabricated on opaque screen such micro baffles can be commercially fabricated by various technologies such as etching holes on a silicon substrate or masking out holes in glass slide with a chromed surface for example the alignment and packaging of systems containing microlenslet arrays and micro baffles is usually completed by the company that designs and fabricates the individual components various approaches including laser alignment are used further discussion of microlenslet arrays can be found in v shaoulov and j rolland u201c compact relay lenses using microlenslet arrays u201d proceedings of the spie international optical design conference 2002 editors p k manhart and j m sasian pp 74 u2013 79 v shaoulov and j rolland u201c design and assessment of microlenslet array relay optics u201d applied optics 42 34 6838 u2013 6845 december 2003 and v shaoulov r martins and j p rolland u201c compact microlenslet array based magnifier u201d optics letters 29 7 1 u2013 3 april 2004 for example referring to fig1 which shows in cross section the compact imaging system 102.