Optical coherence in near fields

Optical evanescent near fields are examples of genuine three-component electromagnetic fields whose coherence and polarization properties cannot always be investigated with the traditional beam-field techniques. In order to access their coherence properties novel near-field nanoprobing methods must be developed. In addition, extra richness to near-field electromagnetic coherence is brought by the possible resonant surface-wave excitations such as surface plasmon polaritons whose presence may significantly alter the statistical properties of near fields.

At UEF we are developing the one-probe and two-probe polarization and coherence detection methods for the quantification of optical beams and near fields. The work benefits from the nanofabrication facilities of UEF where various nano-particle probes can be fabricated. We also focus on the effect of surface plasmon polaritons and the analysis of their coherence properties.   



[1] A. Norrman, S. A. Ponomarenko, and A. T. Friberg, "Partially coherent surface plasmon polaritons", EPL, in press.

[2] L.-P. Leppänen, K. Saastamoinen, J. Lehtolahti, A. T. Friberg, and T. Setälä, ‘’Detection of partial polarization of light beams with dipolar nanocubes’’, Opt. Express 24, 1472 (2016).

[3] L.-P. Leppänen, K. Saastamoinen, A. T. Friberg, and T. Setälä, “Detection of electromagnetic degree of coherence with nanoscatterers: comparison with Young's interferometer”, Opt. Lett. 40, 2898 (2015).

[4] A. Norrman, T. Setälä, and A. T. Friberg, “Partial coherence and polarization of a two-mode surface-plasmon polariton field at a metallic nanoslab”, Opt. Express 23, 20696 (2015).

[5] A. Norrman, T. Setälä, and A. T. Friberg, “Long-range higher-order surface-plasmon polaritons”, Phys. Rev. A 90, 053849 (2014).

[6] L.-P. Leppänen, A. T. Friberg, and T. Setälä, “Partial polarization of optical beams and near fields probed with a nanoscatterer”, J. Opt. Soc. Am. A 31, 1627 (2014).