Spectral and global diffuse properties of high-performance translucent polymer sheets for energy efficient lighting...

Area of Science:

• Materials Science
• Optics
• Polymer Science

Background:

• Translucent polymer sheets with dopant particles are used in lighting applications.
• Existing optical models do not fully account for light loss mechanisms in these materials.

Purpose of the Study:

• To present a visible and near-infrared spectral study of translucent polymer sheets.
• To introduce and validate a new optical parameter, side loss (S(T)), for improved light behavior modeling.
• To analyze the impact of sheet thickness and dopant levels on optical properties.

Main Methods:

• Spectral measurements of diffuse, specular, and total reflectance and transmittance.
• Measurement of absorptance as a function of sheet thickness and dopant concentration.
• Introduction and application of the side loss (S(T)) parameter to account for trapped radiation.

Main Results:

• Optical properties (reflectance, transmittance, absorptance) approach ideal behavior for lighting applications.
• The side loss (S(T)) parameter exhibits strong spectral characteristics.
• Three distinct regimes of specular and diffuse component behavior were identified, linked to total internal reflection (TIR) and side loss.

Conclusions:

• The side loss (S(T)) parameter is crucial for fully characterizing optical performance in translucent polymer sheets.
• The findings provide a more accurate model for light management in polymer-based lighting applications.
• Understanding spectral dependence of optical parameters is key for optimizing material design.