Microsystems have evolved from laboratory curiosities to pervasive constituents of a colorful spectrum of technical products. We can shake our MP3 players to change the song order; print on square meters of paper at 600 dot per inch resolution; have our doctors perform on-the-spot diagnostics; interact with computer games through our body motions; or have our lives saved by an inflated airbag: all these are possible because a microsystem is embedded somewhere, usually as invisible as it is indispensable.

The micro-electro-mechanical systems that first emerged from university laboratories in the 1980s combined mechanics with the technologies of electronics, leading to the term MEMS. But the technology has expanded enormously since then, so that the microelectronics and micromechanics of the germinal MEMS field now include microfluidics, microacoustics, micromagnetics, microchemistry, microbiology, and, not least, micro-optics. The integration of these disparate disciplines into highly functional microsystems with myriad applications is a key reason for the explosive development of these technologies, and as a result, the essence of much microsystems research is now often highly interdisciplinary.

Of these diverse disciplines, optical microsystems have seen particularly strong development, due primarily to the insatiable demand for communications bandwidth. Long- and medium-range telecommunications networks are almost completely optical, and it is the availability of micro-optical components, such as laser diodes, microlenses, fiber couplers, photodetectors, modulators and optical switches, and their integration into complex communications subsystems, that allows us to convey hundreds of petabytes about the planet… daily.