Photonics, Optics and Lasers

Long coils of optical waveguides—any structure that can guide light, like conventional optical fiber—can be used to create a time delay in the transmission of light. Such photonic delays are useful in military application ranging from small navigation sensors to wideband phased array radar and communication antennas. Although optical fiber has extremely low signal loss, an advantage that enables the backbone of the global Internet, it is limited in certain photonic delay applications. Connecting fiber optics with microchip-scale photonic systems requires sensitive, labor-intensive assembly and a system with a large number of connections suffers from signal loss.

Many essential military capabilities—including autonomous navigation, chemical-biological sensing, precision targeting and communications—increasingly rely upon laser-scanning technologies such as LIDAR (think radar that uses light instead of radio waves). These technologies provide amazing high-resolution information at long ranges but have a common Achilles heel: They require mechanical assemblies to sweep the laser back and forth. These large, slow opto-mechanical systems are both temperature- and impact-sensitive and often cost tens of thousands of dollars each—all factors that limit widespread adoption of current technologies for military and commercial use.

The Direct On-Chip Digital Optical Synthesizer (DODOS) program seeks to create a technological revolution in optical frequency control analogous to the disruptive advances in microwave frequency control in the 1940s.

Laser beam-steering is a critical enabler for military and civilian applications including autonomous navigation, chemical-biological sensing, precision targeting and communications. Current beam-steering systems often rely on large, slow, opto-mechanical devices such as the optical gimbal. The gimbal, however, tends to be the largest, slowest and most expensive component in the optical system. Drawing on phased array concepts that revolutionized RADAR technology, the Short-Range, Wide Field-of-View Extremely agile, Electronically Steered Photonic Emitter (SWEEPER) program will develop a compact, agile alternative to mechanical beam-steering.

Mr. Trung Tran joined DARPA as a program manager in the Microsystems Technology Office in October 2015. Tran earned a Bachelor of Science degree in electrical engineering from the US Air Force Academy and a Master of Business Administration degree from The Wharton School of the University of Pennsylvania. While in the Air Force, he was stationed at Fort Meade and Hanscom Air Force Base working at the Air Intelligence Agency. In those roles, he developed cryptographic chips and command and control networks, which focused on reducing the amount of time between the acquisition of sensor data and the use of that data by shooters or, more generally, weapons systems. He received four medals in recognition of his work in these areas.