Overcoming Integrated Photonics Challenges to Enable Next-Generation Optical Microsystems

After many years of directed investment, integrated photonics technologies have begun to enable sophisticated solutions for fiber-optic communications. The increasing maturity and availability of photonic integrated circuits will ultimately enable a variety of revolutionary chip-scale applications including LIDAR, chemical and biological sensing, precision metrology, quantum information processing, and free-space laser communications. However, providing impact in applications beyond datacom has proved challenging because the toolset developed for digital communications often fails to meet the broader needs of new applications. This talk describes DARPA efforts to improve passive and active integrated photonics components, along with relevant programs that are driving technology innovation.
The Modular Optical Aperture Building Blocks (MOABB) program is an effort to develop optical LIDAR using planar photonics components in the place of bulky optics and slow, costly mechanical beam steering elements. MOABB creates an optical phased array which combines coherent light from individual emitter elements placed on a wavelength-scale pitch. Electrically-addressed phase modulators control directionality for transmit and receive functions. Key MOABB device challenges include the dense integration of small phase modulators, high-power tunable lasers, and high-speed drive electronics.
The Direct On-chip Digital Optical Synthesizer (DODOS) program seeks to develop a chip-scale optical frequency synthesizer using a self-referenced optical frequency comb to precisely control the output of a narrowband tunable laser. DODOS has driven the development of high Q microresonators, chip-scale modelocked lasers, efficient frequency doublers, and wideband passive elements that operate with low loss across an octave of spectrum.