STTR Phase I: Development of Materials for Optical Band Gaps in Magneto-Photonic Crystals for Switching and Biosensor Applications

This Small Business Technology Transfer (STTR) Phase I project seeks to develop new types of optical band gaps inside the Brillouin zone in magneto-photonic crystals that will be extremely responsive to external stimuli. These band gaps arise as a result of the hybridization of differently polarized optical modes in a magneto-optic photonic crystal environment. Their formation in functional photonic crystals permits the magnetic control of the crystals' optical response for fast switching applications. The problem to be addressed in this project is the materials requirements for the formation of these magnetically tunable optical band gaps in birefringent non-reciprocal periodic magneto-optic garnet films with large bandwidth. Liquid Phase Epitaxy of thin magneto-optic garnet films on custom substrates will be optimized for all these properties. The films will be characterized by the lithographic and focused-ion-beam patterning implementation of magneto-photonic crystal structures in planar waveguides, which will be used to demonstrate the effectiveness of this approach in achieving the desired optical band gaps. The broader impact/commercial potential will be the development of multi-functional smart materials with commercial applications, as highly sensitive on-chip biosensors, controllable fast optical switches, filters and modulators and magnetic field/current sensors. The detection and analysis of biochemical substances has vast applications in environmental monitoring, biomedical research, healthcare, and homeland security. Optical biosensors constitute an important and powerful tool for the detection of multiple types of analytes ranging from bacteria and bacterial spores to virus and DNA, as well as toxic and non-toxic substances. An interesting feature of the degenerate band gap photonic crystals is the ability to tune a band gap, thus making the structure attractive for the development of optical filters or switches. Optical switching is used in the routing of optical signals for telecommunications and in logic operations. Magneto-optic switching times faster than liquid-crystal, thermal or mechanically based switches are possible. Optical fiber magneto-optic sensors have specific applications in the areas of infrastructure, electric power, automotive, power electronics, aerospace, military, hazardous environments, educational and non-destructive testing. This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).