Z-Link Laser Attenuator

Z-Link Laser Attenuator


Manufacturing License Available
U.S. Pat., 4,664,484


      This is a variable laser attenuator that uses a 3-link mechanism in a “Z” pattern to maintain the output beam co-axial with the input beam.  The device can be inserted into an existing high-energy laser path to safely work in the beam downstream.  
     The device makes use of the variable reflectivity of dielectric materials (glass, fused silica, etc.) at different angles.  At Brewster’s angle (≈56° from normal, for glass) the reflectivity of polarized light is zero.  As that angle increases the reflectivity increases to 100% at grazing incidence.  Only one dielectric surface is needed, shown in the first position, with the remaining reflectors being fully-reflective mirrors.  The balance of the light, not reflected off the first reflector, is absorbed or refracted through the material into a light trap (not shown).


      In order to compensate for the 2X-speed effect of a mirror, half speed ball-bearing assemblies are used at each joint.  The slowly rotating mirror causes reflected light to follow the arm that is rotating twice as fast as the mirror.  

     These half-speed joints work somewhat like a Lazy-Susan on a dinner table, with ball bearings (trapped between the stationary bottom and the rotating top) where the ring of balls rotates half as fast as the top.  


Hines’ notebook entry:
p. 37


      HinesLab is actively seeking licensees to commercialize this technology.  This is not a product being offered for sale to end users.  To discuss licensing, please contact Steve Hines at:

Glendale, California, USA