In-Line Beam Steerers are convenient devices that precisely change the angle or alignment of optical beams without the use of mirrors. Unlike Risley prisms, In-Line Beam Steerers move the beams in a cartesian coordinate system rather than in a polar coordinate system. With a single adjustment, the In-Line Beam Steerer deflects the beam either horizontally or vertically. One In-Line Beam Steerer replaces typical two-mirror systems and makes adjustments easier. The In-Line Beam Steerer is an adjustable wedge formed by a plano-concave and a plano-convex lens that are connected to one another using a thin layer of index-matching fluid. Displacement of one lens with respect to the other changes the wedge angle, thereby steering the beam.

Steering resolution is controlled by the radius of the two plano optics.  Our current models offer 14 microrad/deg angle sensitivity, but custom models can be made with a factor of 10 better sensitivity.