Opto-thermal design of a white light point source based on high power blue laser diodes (Conference Presentation)

Abstract

When designing white light systems, the use of laser diodes allows for an accurate control of the intensity pattern when combined with advanced optical components. This approach however also imposes severe challenges regarding the thermal packaging of the colour conversion element (CCE) that is used in combination with the blue laser diode(s). To correctly assess the performance of white light systems based on laser diodes, it is critical to account for the optical and thermal effects. We propose an opto-thermal design that produces white light with a very small spatial extent, approaching a point source. We optimize the system's performance with an opto-thermal simulation tool that models both the optical and thermal properties in a realistic and accurate manner. This tool allows estimating the maximum incident optical power that still results in thermally stable operation. We show that even when using high power laser diodes to excite a millimetre scale CCE, it is still possible to have a thermally stable white light system.