to provide a direct link between radio frequency (RF) and optical standards, which took several rooms to perform at only a few laboratories around the world a decade ago. Now this capability is commercially available. Since the NRC’s 1998 study, miniature atomic clocks on a chip have been developed to provide precise local measurements. Quantum cascade lasers on the market extend the range of chip-scale laser sources for near and remote sensing applications into the middle-infrared wavelength range of the electromagnetic spectrum (3-30 µm). The field of terahertz imaging has matured to the point of deployable systems in airports and other points of entry into our nation for the secure and efficient passage of trade goods. New construction—such as bridges, tunnels, dams, skyscrapers, pipelines, railroad tracks, and power plants—and renovation of civilian and military infrastructure around the world routinely have many kinds of active and passive optical sensors (for example, of vibration, temperature, strain, displacement, and cracks) embedded for the real-time monitoring of operation and for the forecasting of hazardous conditions before disaster strikes. Optical sensors are also common in cars, trucks, airplanes, and ships.
Optics and photonics advances have enabled advances in precision manufacturing, which have enabled further improved sensors. Low-cost, high-resolution cameras in cell phones now make advanced digital imaging available to a substantial fraction of the world’s population with capabilities comparable with the best high-end cameras of a decade ago. Those components will enable a new wave of secondary niche markets that have the potential to have a significant impact on the U.S. economy and job pool. This broad growth of optical sensing and metrology—from the most precise scientific applications to universal consumer devices—makes the next decade an exciting time for optics and photonics in sensing and measurement, in research, and in consumer and industrial applications and offers significant opportunities for U.S. leadership.
Advanced photonic measurements and applications have had a profound impact on our daily lives. For example, GPS has had a significant impact on navigation. In the late 1990s, consumer GPS devices were only beginning to enter the market. Now this capability is a commonplace consumer item found in cell phones, car navigation equipment, and even pet identification tags. GPS relies on precision timing to enable high-resolution positioning, which also enables high data rates and long-range communications. That timing is enabled by several advances in photonics, such as compact atomic clocks on a chip (see Figure 8.1). Sensing and metrology have enabled a new level of integrated-circuit (IC) manufacturing, which has driven the entire consumer electronics industry. Those advances have