Assembly of micro-optical devices using magnetic actuation

We report a high-yield and high-efficiency assembly technique for three-dimensional micro-optical components, including Fresnel lenses, optical gratings, and comer cube reflectors. The three-dimensional assembly process and the optical performance of the assembled components is presented. The angular displacement of individual microstructures is controlled by varying the volume of the magnetic material and through the addition of a flexural-beam loading mechanism to the hinged microstructure. The normal force caused by the deflection of the beam enhances the stability of these devices after they are assembled. The stability of the corner cube reflector is further enhanced by a hooking mechanism in the microstructure. Tests conducted with a He-Ne laser confirm that the measured performance of the Fresnel lens and optical grating correlate well to the expected theoretical values. We also demonstrate the capability for parallel actuation of large arrays of optical components under a global (wafer scale) external magnetic field.