Micromachining for optoelectronic systems

We review the current state of the art of micromachining in optoelectronic systems, and discuss in detail the progress of the free-space micro-optical bench (FSMOB) project at UCLA. The FSMOB comprises passive optical elements (diffractive and refractive lenses, gratings, beamsplitters, filters, etc.), micropositioners (translation and rotation stages), and microactuators. Because the micro-optical elements on the FSMOB are precisely positioned by photolithography, they can be "pre-aligned" during the photomask layout. The fabrication of the out-of-plane optical elements are compatible with the micromotors and other microactuators. Therefore, the optical elements can be monolithically integrated with micropositioners and microactuators for optical switching or scanning, or to achieve fine optical alignment.