Concentric re-emission pattern from a planar waveguide with a thin uniform luminescent layer

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Planar waveguides with luminescent layers exhibit concentric re-emission patterns when excited by light.
• Understanding these patterns is crucial for applications like luminescent solar concentrators and energy-harvesting displays.

Purpose of the Study:

• To develop an analytical expression describing the re-emission pattern in a luminescent waveguide.
• To provide insights into the physical processes governing light re-emission and energy transfer.

Main Methods:

• Formulation of an analytical expression based on the sequential events within the waveguide.
• Modeling the generation of angle-dependent photoluminescence spectra.
• Accounting for reflection at the waveguide-air boundary and re-absorption within the luminescent layer.

Main Results:

• The derived formula accurately reproduces experimental peak radii observed with organic dyes.
• The model successfully describes the series of events leading to the observed concentric re-emission.

Conclusions:

• The analytical expression offers a quantitative understanding of light re-emission in luminescent waveguides.
• Findings are applicable to optimizing luminescent solar concentrators and mitigating crosstalk in photoluminescent displays.