Multimirror stack for vertical integration of MEMS devices in two-position retroreflectors

A method for directing an optical ray, the method comprising:

• providing a retroreflector comprising a substrate, a moveable micromirror formed over the substrate and adapted to be tilted into at least two distinct positions, and a multimirror stack positioned on the substrate, the multimirror stack including a plurality of fixed structures bonded together, each such fixed structure having a reflective surface;
• propagating the optical ray incident at a predetermined angle with respect to the substrate to provide a first retroreflection of the optical ray, such first retroreflection including a reflection off the moveable micromirror and a reflection off a first of the plurality of fixed structures;
• and
• changing a tilt of the moveable micromirror to retroreflect the optical ray with a second retroreflection that includes a reflection off the moveable micromirror and a reflection off a second of the plurality of fixed structures.

A retroreflector comprising:

• support means;
• moveable reflection means formed over the support means and adapted to move into at least two distinct positions;
• and
• fixed reflection means positioned on the support means, the fixed reflection means configured such that an optical ray incident at a predetermined angle with respect to the support means is retroreflected for the at least two distinct positions of the moveable reflection means along distinct paths, each such path including a reflection off the moveable reflection means and off a portion of the fixed reflection means.