Luna will team with Dr. John Bowers of UCSB to continue development of an Optical Frequency Domain Reflectometry (OFDR) system-on-chip using heterogeneous silicon photonics to enable a minimal weight structural health monitoring system. This system-on-chip will be the building block for distributed sensing interrogation systems that are the size of a deck of playing cards. This lightweight, rugged, and miniature system will enable OFDR-based SHM sensing applications in space, where size and weight constraints are paramount. Phase I successfully proved the feasibility of the heterogeneous silicon tuning laser chip and distributed fiber optic sensing using a silicon OFDR chip in the laboratory. During Phase II, Luna will optimize the silicon tuning laser and OFDR designs in preparation for fabrication of a full OFDR system-on-chip, demonstrating the miniaturization and weight savings necessary for deep space SHM applications. Overcoming technical hurdles in laser tuning, polarization control, and delay line length are critical to successful commercialization of the innovation for SHM sensing, and will provide advancement in the state-of-the-art of silicon photonics and structural health monitoring.
Luna’s proposed innovation will address the four chief technical challenges of deep space travel: mass reduction, reliability, affordability, and radiation hardening. The reduction of volume/mass/power of electronics and elimination of copper wires will maximize the science return for future missions. CMOS fabrication of optical networks will allow for ruggedization and increases in reliability as well as reductions in cost. Radiation hardening of a continuous wave tunable laser will provide a reliable building block for future missions such as Discovery, New Frontiers, Mars, and Europa-Jupiter. Applying OFDR to structural health monitoring will benefit launch vehicles, space stations, and inflatable habitats. Implementing OFDR as a photonics system-on-chip for SHM will achieve the size, weight, and power requirements for these innovative space applications. Teaming with UCSB (part of IP-IMI/AIM Photonics) adds credibility to achieving a viable OFDR-based photonics product for structural health monitoring.
The successful commercialization of an OFDR system-on-chip will revolutionize the fiber optic distributed sensing market. Attaining the unrivaled spatial resolution of OFDR in a miniaturized, lightweight, and low-cost package will enable many new sensing applications. Distributed fiber optic sensing is a perfect fit for embedding strain sensors in composite structures in aerospace and automotive vehicles. This innovation will be the first step to achieve in-flight, online SHM of aeronautical and space launch vehicle structures. The high-definition sensing of OFDR can identify defects, delamination, and stress concentrations that traditional strain gage sensors miss. The reduction in cost and size, weight, and power (SWaP) enabled by this research will be crucial to successful implementation. Advancing the state-of-the-art in structural health monitoring will increase safety and efficiency in aircraft and automotive transportation, and can also be adapted to benefit civil infrastructure like bridges and buildings.