Anomalous light scattering in photonic cholesteric liquid crystals

ABSTRACT

We have carried out polarisation and angle-resolved measurements of the light scattered from photonic cholesteric liquid crystals. Both in samples doped with laser dyes and in inactive (non-doped) samples we have observed pronounced directional dependences of the scattered light, finding angular ranges where the scattering is greatly enhanced and regions where the effect is almost suppressed. Moreover, the total amount of scattered light has also been found to depend strongly on the polarisation and direction of the incident beam. All the results have been interpreted successfully in terms of a simple expression proposed for the scattering cross section, in which the density of states of the ingoing and outgoing beams plays a major role. The expression would be applicable not only to cholesteric liquid crystals but to any one-dimensional photonic material.

Graphical abstract

KEYWORDS:

• Photonic structures
• scattering
• cholesteric liquid crystals
• distributed feedback lasers

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Euskal Herriko Unibertsitatea [Project GIU18/146].