Advantages of Combining Lasers with Phosphors
Laser phosphors are enabling a new generation of compact and powerful light sources. Most current solid-state lighting (SSL) systems used for general illumination are based on the phosphor converted LED (pcLED) architecture, which offers a practical and mass producible structure for white light generation. Laser-based SSL devices also exist in limited applications such as automobile headlights and in various image projection devices such as laser-based Digital Light Processors (DLPs).[1] SSL emitters can be combined with selected phosphor materials to produce tailored optical sources by energy down-conversion for applications ranging from human-centric lighting to scientific illumination for spectroscopy and various instruments. Furthermore, the down-conversion materials in remote phosphor film configuration enables the production of LED devices with customized spectral distribution for a wide range of specialty applications at low costs using roll-to-roll manufacturing [2]
Compact and High Quality Point Light Lasers
Laser phosphors can help produce very compact lamp sources. For a comparable amount of light, a traditional halogen high-beam automobile headlight requires a diameter more than 7 times that of a phosphor-based laser lamp technology. For example, by combining a blue 445nm laser with red-green-yellow (RGY) phosphor system, it is possible to produce a source with correlated color temperature around 2900K and color rendering index of 93. Such photometrics are comparable to warm white lamps generally produced using royal blue LEDs and phosphors, as illustrated in the figures below. [3]
Blue Laser @ 445nm with Phosphors
Blue LED @ 450nm with Phosphors
[1] H. Menkara, Z.Kang, C. James, “IR Scene Projection by Optical Down-Conversion”, Proceedings of 2021 IEEE Research and Applications of Photonics in Defense Conference (RAPID), August 2021.
[2] H. Menkara et. Al., “Roll-to-roll Manufacturing of RGB Phosphor Sheets for Solid State Lighting and Large Area Flexible Displays”, SID Symposium Digest of Technical Papers 45(1), June 2014.
[3] Menkara, H., “Application of Lasers in Phosphor Material Development for Solid-state Lighting”, 3rd Edition of Virtual Online Conference on Advancements of Lasers, Optics and Photonics; September 2021.