Abstract

When the hypotenuse of a dielectric prism coated with the correct thickness of a suitable metal is illuminated with p-polarized light at the appropriate angle of incidence beyond critical the light couples into a bound surface wave on the outer surface of the metal. The coupling is marked by a sudden sharp and deep dip in the internal p-reflectance of the prism. This phenomenon is known as Surface Plasmon Resonance and this particular form of coupling is known as the Kretschmann [ 1 ] configuration. The resonance is a very sensitive function of the surface conditions and changes in its angular position and shape can be used as a probe of surface conditions. In particular it may be, and has been [ 2 ], used to track changes in a thin film deposited over the metal surface. The better the optical performance of the metal, the narrower is the resonance. The work reported here uses silver. Silver has very high optical performance and gives excellent resonance curves but suffers from long term durability problems.

© 1995 Optical Society of America