Low Divergence Structured Beam In View Of Precise Long-Range Alignment

A new method of generation a Structured Laser Beam (SLB) with non-diverging central core was proposed and is promising for creating long distance multipoint alignment systems. This beam generated by set-up consisting two convex lenses in Kepler telescope arrangement. The first one high refractive index ball lens, second standard lens. beam, cross-section light dark concentric circles, propagates over large distance. the SLB has very small divergence which can be tuned. 10 μrad proven experimentally. In this experiment, initial diameter μm, its 1.5 mm at 150 m, show ability use as fiducial reference line. seemingly lies beyond diffraction limit laser beams.