Research Projects

The study proposes the development of a laser-driven phosphor-converted (LD-PC) full-spectrum white light source for simultaneous illumination and visible light communication applications. The method involves a high-power blue laser diode coupled with a YAG:Ce+3 phosphor layer for laser photon scattering and fluorescence conversion through absorption. The scattered blue photons and fluorescence yellow photons combine to generate broad-band white light with high color purity. Multiple phosphors with high quantum yield will be used to achieve full-spectrum white light LD-PC source. Losses due to quenching, absorption, and scattering will be investigated. One major problem with the blue LD-PC with multiple phosphors is color/spectral non-uniformity across space. To achieve color/spectral uniformity, a solution is proposed by mixing multi-color phosphors with nano-scatterrers such as TiO2, ZnO, and Alumina nano-particles. An extended white light source with full spectrum color coordinates and CRI greater than 90 will be developed. A fraction of the pump photons (blue color) will be used for visible light communications (VLC) in free space. The communication channel will couple with the laser source through on-off-key modulation. The developed system has great applications for green photonics, an environmentally friendly technology. Future prospects include using the same source and setup for both lighting and communication, resulting in a sun-like spectrum and high-speed communication.