Abstract: High sensitivity is obtained at larger resonant incident angle if negative diffraction order of metallic grating is used to excite the surface plasmon. A highly sensitive grating-based surface plasmon resonance (SPR) sensor is designed for the hydrogen detection. A thin palladium (Pd) film deposited on the grating surface is used as transducer. The influences of grating period and the thickness of Pd on the performance of sensor are investigated using rigorous coupled-wave analysis (RCWA) method. The sensitivity as well as the width of the SPR curves and reflective amplitude is considered simultaneously for designing the grating-based SPR hydrogen sensor, and a set of optimized structural parameters is presented. The performance of grating-based SPR sensor is also compared with that of conventional prism-based SPR sensor. 12． M. J. Jory, P. S. Vukusic, and J. R. Sambles, "Development of a prototype gas sensor using surface plasmon resonance on gratings," Sens. Actuators B 17, 203-209 (1994). 13． C. R. Lawrence, N. J. Geddes, D. N. Furlong, and J. R. Sambles, "Surface plasmon resonance studies of immunoreactions utilizing disposable diffraction gratings," Biosens. Bioelectron. 11, 389-400 (1996). 14． D. Zhang, P. Wang, X. Jiao, G. Yuan, J. Zhang, C. Chen, H. Ming, and R. Rao, "Investigation of the sensitivity of H-shaped nano-grating surface plasmon resonance biosensors using rigorous coupled wave analysis," Appl. Phys. A 89, 407-411(2007 5056-5070 (1974). 18． D. R. Shankaran, K. V. Gobi, T. Sakai, K. Matsumoto, K. Toko, and N. Miura, "Surface plasmon resonance immunosensor for highly sensitive detection of 2, 4, 6-trinitrotoluene," Biosens. Bioelectron. 20, 1750-1756 (2005). 19． B. Chadwick, J. Tann, M. Brungs, and M. Gal, "A hydrogen sensor based on the optical generation of surface plasmons in a palladium alloy," Sens. Actuators B 17, 215-220 (1994)
