Optical engineering comes to Lilliput

Diminutive Lilliputians detained a ship-wrecked Gulliver when he washed ashore in Jonathan Swift's 18th-century cautionary tale Gulliver's Travels. The tiny natives impressed Gulliver with their engineering abilities. "These people are most excellent mathematicians and have arrived to great perfection in the art of constructing machinery of all kinds," he observed. To transport him a mile or so to the great metropolis in Lilliput, an army of hundreds of little builders and engineers felled giant trees, created hoists and scaffolding, and constructed, according to Gulliver's view, a "great engine." Having no motors, they harnessed nearly 1500 of their miniature horses to the platform to pull Gulliver to visit the emperor.

Today, "great engines" are likely to be very small. Compared to the 19th-century Industrial-Revolution-era devices, motors, engines, and instruments seem almost Lilliputian in scale. And semiconductor engineering is creating even tinier versions. A transistor that, decades ago, could be held in your hand is now patterned on silicon wafers as part of complete integrated circuits in fabs, rather than on a wooden workbench.

Optics in Lilliput

Gulliver turned to classical optics to spy on the enemies of Lilliput on the nearby island of Blefuscu with his pocket spyglass. Capturing the enemy fleet assured his freedom to study the native Lilliputians. Many of the animals were so small that Gulliver could barely see them, prompting the comment, "Nature hath adapted the eyes of the Lilliputians to all objects proper for their view; they see with great exactness, but at no great distance." Hence he witnessed ladies threading invisible needles with invisible thread and sewing with aplomb.

Now 20th-century optical engineering is in the Lilliputian world. Great engines, such as diode-laser light sources, are no larger than a grain of sand. Classical optical elements such as filters, refractive lenses, and gratings about the size of a human hair can be created. Human efforts engineered the images on this month's cover with the techniques described on p. 64. These miniature elements can be assembled at the wafer level to create integrated optical devices such as optical pickup heads and fiberoptic switches, leading the developers to proclaim that they can create "silicon micro-optical benches on a chip." If the Lilliputians had these microbenches and tools, who knows what Gulliver would have seen in his travels!