Phosphor Element Optical Waveguide Light Extraction

The patent segments the optical waveguide structure into multiple functional layers including clad layers with different refractive indices and incorporates reflection films at specific locations. This segmentation allows different portions of the waveguide to perform specialized functions: confining light through refractive index differences and reflecting escaped fluorescence back into the waveguide, thereby reducing light loss while maintaining propagation efficiency.

The patent introduces clad layers as intermediary structures between the phosphor layer and the external environment. These clad layers with controlled refractive indices act as mediators that manage light propagation by confining fluorescence within the waveguide through total internal reflection, while reflection films serve as additional intermediaries to redirect escaped light back into the propagation path, thus reducing energy loss.

The patent extracts heat from the phosphor element by introducing dedicated heat conduction paths through the waveguide structure. The clad layers and substrate are designed to conduct heat away from the phosphor conversion region, effectively removing thermal energy that would otherwise cause degradation. This allows higher excitation light densities to be applied without proportional increases in temperature.

The patent changes the thermal management parameters of the waveguide structure by selecting materials with appropriate thermal conductivities for different layers. The clad layers and substrate are chosen to optimize heat conduction, creating a thermal parameter profile that maintains low temperatures in the phosphor region even under high excitation power, thereby preventing thermal degradation while maintaining high fluorescence generation efficiency.