Abstract: Microlithography techniques have provided a means for the development of many useful devices from microcircuits, which made the computer era possible, to micromechanical devices such as motors that are only a few tens of microns across. A new use of a microdevice is presented here which serves to "payback" the art of microlithography as it is a significant contribution thereto. The device of the invention is a unique microdevice made with advanced microlithography techniques which when completed can be used as a new exposure tool for microlithography.A lens array can be as thin as 1/40 of the thickness of the page that this text is printed on, yet have thereon an arrangement of optical lenses powerful enough to replace very sophisticated and bulky, million dollar precision optics.An array of lenses can be fabricated with binary optical device and other techniques.

Abstract: An interferometric apparatus for monitoring changes of the refractive index of An interferometri1capillary tubes comprising a source of coherent light, which is arranged with respect to a capillary tube which is part of a capillary liquid chromatographic system or a capillary electrophoretic system, such that the coherent light beam strikes the capillary tube about perpendicular to its longitudinal extension. In the forward direction of the coherent light beam, behind the capillary tube, the apparatus comprises a photoelectric detector for monitoring a resulting interference fringe pattern and the shifts thereof, which is connected to an evaluation electronics.