SBIR Phase II: Thick Film Garnet Materials for In-Plane Propagation Magnetooptic Devices

This Small Business Innovation Research (SBIR) Phase II project addresses the device and market opportunity for in-plane propagation of light in-planar anisotropy magnetic garnet films for high sensitivity, high speed magneto-optic sensors, switches and modulators. Traditional perpendicular propagation devices require perpendicular magnetic fields and magnetization processes. These are limited in speed and sensitivity by the current materials and the energy required to magnetize the garnet in the perpendicular direction. In the plane of the film, there is almost no energetic barrier to domain rotation. In this project, Integrated Photonics, Inc. (IPI) proposes to reduce that barrier to near zero to make devices of unprecedented sensitivity and speed. The goal is to attain pico-tesla field sensitivities in sensors and gigahertz device frequencies. The latter will enable small, low-power magneto-optic light modulators that are truly a disruptive technology by comparison to current large dimension electro-optic technologies. In Phase I, a materials growth and characterization capability was established and limitations on speed and sensitivity were removed by optimizing material parameters. In Phase II the process will be optimized to achieve the highest optical quality for commercial devices and sensor, switch and modulator devices will be realized in collaboration with customer-partners. Commercially, in-plane propagation in planar thick film Faraday rotators would enable unique new devices. High speed magneto-optic modulators open the door to system integration architecture for wideband communications and software defined radios. In-plane propagation materials have much higher switching speeds than conventional perpendicular Faraday rotators and as such would permit a magneto-optical approach to packet switching. Reduced costs would permit wide deployment in FTTP. High speed, low field magneto-optic switches are attractive for military applications. In-plane propagation magnetic field sensors can be optimized to give unprecedented high sensitivity speeds much higher than can be attained with conventional perpendicular propagation. These sensors would have applications such as wheel and turbine rotation, electric power distribution, monitoring, metering and control and battlefield sensors. The electric power application in particular has potential to revolutionize catastrophic failure prevention in the power grid and reduce power costs at a variety of levels by enabling autonomous reconfiguration. The lack of electrical connectors in fiber optic sensors for explosive, flammable and high voltage environments represents a significant improvement in safety. Smart ships and buildings would find utility both for conservation and efficiency.