Surface plasmon-like sensor based on surface electromagnetic waves in a photonic band-gap material

The design and operating principles of a new type of surface electromagnetic wave sensor are described and demonstrated. The method of operation of this device is similar to surface plasmon sensors except that the surface-active material-a metal film in the case of surface plasmon sensors-is replaced by a one-dimensional photonic band-gap array. The advantages of using a photonic band-gap material instead of a metal film include enhanced sensitivity, physical, and chemical robustness, and the ability to engineer the optical response of the surface active layer to create a device that operates at any optical wavelength. Experimental results are presented that illustrate sensing action by measuring the shift in the surface mode coupling angle with surface loading.