Introduction – LIPA’s Communications Working Group (CWG) Identified the topic of Laser Engine Architecture as an important subject for a technology update Webinar in 2023.
Title: Evolution, Status and Applications of Laser Light Engines for Projection
August 3, 2023, 06:30-0800 US Pacific time
54 people attended representing all LIPA members
Our LIPA Member Speakers
Director R&D – Laser Device and Laser Light Source, Appotronics
Lead off with a review of terminology, the evolution of Laser diodes and Laser-pumped phosphor architectures over the past 10 years; current status and the direction of future developments and applications.
Sr. Product Developer, Projection Engineering, Christie Digital
Focused on “direct” RGB architectures, the rationale for their use, current status, and future development.
Goran Stojmenovik, Ph.D.
Director R&D, Barco NV
Presented Barco’s “agnostic path” for engine architecture development and describe how different approaches can best support an expanding range of application requirements.
Tom Bert, Ph.D.
VP Product, Barco NV
Wrapped up the presentations with a discussion of current status and a new types of laser sources, spatial light modulation and engine architectures to support new high dynamic range (HDR) applications.
- Both major architectures, “Pure” RGB and Laser-Phosphor “La-Ph”, have been under development for nearly 20 years with commercialization beginning around 2008 for La-Ph and 2014 for Cinema RGB
- RGB is used primarily for large screen Cinema and Professional applications
- Highest possible lumen output (75K+) with widest color gamut (near Rec 2020)
- Required for efficient fiber coupling for ultra-high brightness or remote source/modular systems
- Required for special “Cascaded” HDR and High Contrast systems enabled by high f# (small étendue) Laser input.
- Lower output RGB engines are finding applications where they can enable both brightness and resolution from a smaller SLM chip.
- Original Blue Laser Pumped Phosphor (BPP) has evolved into many special architectures, with direct Red, Green and Blue diode “boost” to achieve a target mix of performance optimizations such as higher lumen output, wider gamut, speckle mitigation/reduction, higher wall plug efficiency etc.
- Care must be taken when comparing efficiency metrics (i.e., lm/W), as these can be affected by gamut primaries, white-point, cooling system design, expected lifetime and other system level differences. (Wall plug efficiency should always be considered in the context of other performance metrics.)
- All speakers mentioned that operating efficiency (lm/wall plug watt) has become a very important performance metric for Cinema Projectors and all high duty cycle applications due to the recent and rapid increases in power costs.
- A new type of architecture called “light Steering” was described, where additional RGB light is efficiently added to the base laser-illumination with a spatially controlled distribution, increasing the dynamic range and maximum pixel brightness of the final image.
LIPA will hold a companion Tech Webinar on Wide Color Gamut/Volume September 28, 2023, open to members and the A/V public.