3-DIMENSIONAL MICRO-FRESNEL OPTICAL-ELEMENTS FABRICATED BY MICROMACHINING TECHNIQUE

The authors report, for the first time, a three-dimensional binary phase micro-Fresnel optical element standing perpendicular to the substrate. The optical element is fabricated by a micromachining technique. The element has a diameter of 650mum a focal length of 0.5 mm and an optical axis of 1 mm above the surface of the substrate. Light from an optical fibre is sucessfully collimated by the micro-optical element, and the beam profile closely approximates a Gaussian shape.