Chip-Scale Optical Receivers for Communications

OBJECTIVE: Develop a small SWAP-C (chip-scale) optical receiver that overcomes current limitations such as field-of-view (FOV) and pointing and tracking (PAT) enabling communications for highly mobile vehicular and personal/on-body applications. DESCRIPTION: The radio frequency (RF) spectrum, relied upon for wireless communications, is increasingly congested and subject to interference that reduces system performance. Obtaining the bandwidth necessary for the high data rates demanded by modern applications is extremely expensive within licensed bands, and permissible use of the unlicensed bands entails various design restrictions. Free space optics (FSO) systems that can communicate using lasers eliminate these problems since the optical bands are unregulated, and the extreme directivity of lasers prevent interference with nearby receivers. Furthermore, the large amounts of available bandwidth with this approach can offer very high data rates. Unfortunately, while current commercially available FSO systems are suitable for fixed-site point-to-point applications with mast/tower-mounting, they are unsuitable for highly mobile applications with stringent size, weight, and power (SWAP) requirements. Additionally, the high-cost of FSO makes it impractical to field in very large quantities for military use and rules out potential civilian applications. Photonic integrated circuit (PIC) based FSO address all of these problems. Designed to be fabricated on an integrated circuit, PIC-based FSO can achieve size and weight reductions of multiple orders of magnitude relative to traditional FSO designs, and, when fabricated in production quantities, the costs of these PICs are minimal compared to FSO system component costs. In addition, because optoelectronic techniques enabling extremely rapid beam-steering can be used instead of mechanical steering, chip-scale systems can support on-the-move applications. Because of these capabilities and attributes the use of chip-scale FSO holds great promise for incorporation into networks as a means to alleviate the growing demand for RF spectrum while providing high data rate communications in a low SWAP-C design. Although chip-scale FSO components have been fabricated and demonstrated at various levels of maturity, additional development of the components and receiver design is needed in order to realize the promise of the technology. Current designs are limited in field-of-view (FOV) especially across wide bandwidths and implementation of high-speed pointing and tracking (PAT) is limited. C5ISR Center seeks the design and development of a chip-scale optical receiver that overcomes these challenges and enables low SWAP-C high data rate communications for highly mobile applications. In particular, C5ISR Center seeks a wide FOV (>= 45 degrees) wide-bandwidth (1 10 GHz) receiver capable of pointing and tracking and high rates (=45 degrees in azimuth and elevation) in a compact form-factor (