Magneto-optic Surface plasmon Resonance Ti/Au/Co/Au/Plastics Configuration and Sensitivity
Magnetooptical (MO) materials are new class of material that merges magnetics, optics and plasmonics sub-fields of science. The main components of MO material are ferromagnetic and ferromagnetic oxide materials such as Co, Fe, Ni, Magnetite, etc. where change in permittivity tensor is accompanied by the presence of magnetic spin or by applied external field. The permittivity tensor also depends on the frequency of the incident optical radiation.
Magneto-optic (MO) materials have application in wide-areas. These include determination of the average free carrier effective mass, detection of magnetic impurities; dynamic studies of film growth, MO filters as atomic line filter, memories, field sensors, modulators, and integrated optoelectronic devices, like optical circulators, isolators and switchers. MO materials have also been used in drives using thermomagnetic recording and magnetic recording [3, 4]. Other fields include MO microscopy and spintronics. The most recent application of MO material is biosensing where effort is being made to develop world’s most sensitive biosensors.
Although the discovery of magneto-optic (MO) effects in metals and dielectric is not new (It was first demonstrated by Michael Faraday in 1945), its importance in magneto-optic based sensing and imaging has emerged only in the last few decades   . MO in spintronics and recording have been found application only begining of 21st century.One of the recent application of magnetic field on bio-sensing is demonstrated here . Figure shows a structure in Kretchmann configurations similarly to shown in our prior work . It includes a right-angled isosceles prism, lenses, index matching liquid, buffer layer, a substrate with transducer/sample, and optical laser source and photo detection (PD) system. The direction of applied magnetic field, H is along the Co/Au interface  . The SPR of the MOSPR configuration having nano-scale layers of Co and Au in conjuction with 2 nm Ti adhesive layer shown on the bottom.
Figure on the top shows the differences between the SPR responses in air and water media. Sensitivity comparisons between gas and liquid media. As shown in the diagram. Both the SPR and MOSPR sensor responses in air medium is found to be stronger and is relevant for environmental and pollution studies. The sensor response in water medium is also found to be stronger compared to the sensor response of conventional SPR sensors, and is highly relevant for bio-sensing that involves liquid media.
- Conrad Rizal; Boris Niraula; Howard Ho Wai Lee; Bio-Magnetoplasmonics, Emerging Biomedical Technologies and Beyond. Journal of Nanomedicine Research 1970, 3, 1-6, 10.15406/jnmr.2016.03.00059.
- A.K. Zvezdin and V.A. Kotov. Modern magnetooptics and magnetooptical materials; CRC Press: Canada, 1997; pp. 404.
- Manvir S. Kushwaha; Plasmons and magnetoplasmons in semiconductor heterostructures. Surface Science Reports 1970, 41, 1-416, 10.1016/S0167-5729(00)00007-8.
- Eric E. Fullerton and Jeff R. Childress; Spintronics, Magnetoresistive Heads, and the Emergence of the Digital World. Proceedings of the IEEE 1970, 104, 1787-1795, 10.1109/jproc.2016.2567778.
- Daria O. Ignatyeva; Grigory A. Knyazev; Pavel O. Kapralov; Giovanni Dietler; Sergey K. Sekatskii; Vladimir I. Belotelov; Magneto-optical plasmonic heterostructure with ultranarrow resonance for sensing applications. Scientific Reports 1970, 6, 28077, 10.1038/srep28077.
- Conrad Rizal; Simone Pisana; Ivan Hrvoic; Eric E Fullerton; Eric Fullerton; Microstructure and magneto-optical surface plasmon resonance of Co/Au multilayers. Journal of Physics Communications 2018, 2, 055010, 10.1088/2399-6528/aac0e0.
- Conrad Rizal; Simone Pisana; Ivan Hrvoic; Improved Magneto-Optic Surface Plasmon Resonance Biosensors. Photonics 2018, 5, 15, 10.3390/photonics5030015.
- Conrad Rizal; Microstructure, Surface Plasmon, Magneto-Optic Surface Plasmon, and Sensitivity Properties of Magneto-Plasmonic Co/Au Multilayers. IEEE Transactions on Magnetics 1970, 6, 1-9, 10.1109/tmag.2018.2854663.