Surface wave sensors based on nanometric layers of strongly absorbing materials

We demonstrate the excitation of guided modes in thin layers of strongly absorbing chalcogenide glasses. These modes are similar to surface plasmon polaritons in terms of resonance width and shift with changes in the permittivity of the surrounding medium. We exploit these characteristics to demonstrate a high sensitivity chalcogenide glass refractive index sensor that outperforms gold surface plasmon resonance sensors at short wavelengths in the visible. This demonstration opens a new range of possibilities for sensing using different materials.