R. Klug et Kh. Brenner, Implementation of multilens micro-optical systems with large numerical aperture by stacking of microlenses, APPL OPTICS, 38(34), 1999, pp. 7002-7008
In the field of micro-optics there is a demand for objectives with large nu
merical aperture (NA). One example is optical storage in which a NA greater
than 0.5 is required. For planar microlenses the NA is determined by means
of the maximal index difference and the degree of exchange and reaches typ
ical values of 0.13-0.2. Thus stacking is needed to build high NA objective
s from planar microlenses. An additional benefit of stacking lenses is the
possibility to correct for different types of aberrations. We realized two
stacked systems: an array of micro-objectives with a NA of 0.45 from three
microlens arrays and a confocal sensor head from four microlens arrays and
one pinhole array mask. (C) 1999 Optical Society of America OCIS codes: 110
.2760, 130.3120, 180.1790, 110.0110, 130.0130, 180.0180.