Interference effects on indium tin oxide enhanced Raman scattering

Optical interference is known to alter the intensity of Raman scattering signals. Its effect on enhanced Raman scattering from embedded indium tin oxide (ITO) nano-island arrays prepared by pulsed laser deposition of ITO films with different thicknesses on Si templates with nano-scale roughness are studied. Optical self-interference of the incident, scattered, and emitted light is observed to modulate the intensity and shape of the Raman signals as well as fluorescence background. The fluctuations in the Raman signals and fluorescence background can be explained by a theoretical model considering multiple reflections at the surface and interface. This interference effect must be taken into account in the investigation of enhanced Raman scattering from ITO.