A small and efficient hydrogen sensor using surface plasmon resonance in an
integrated optical waveguide is reported. The waveguide properties are inf
luenced by a thin palladium layer whose optical constants depend on concent
ration of hydrogen in surrounding gaseous medium. A modal analysis of the s
ensor structure is performed and a simple sensor model is proposed. Finally
, experimental results are presented detection of hydrogen concentration as
low as 4% is demonstrated. (C) 2001 Elsevier Science B.V. All rights reser
ved.