Sep 17, 2020

We’ve only just begun: Innovation lives in the world of white light

Category: Illumination
Lumileds LUXEON Fusion technology enables the next step in human-centric lighting, providing the option to adjust light levels throughout the day to complement a changing ambient environment.

Lumileds LUXEON Fusion technology enables the next step in human-centric lighting, providing the option to adjust light levels throughout the day to complement a changing ambient environment.

Twenty years ago, the best ‘white’ LEDs produced a weak, heavily tinted output which most observers would have classed as more yellow/green than white. These first attempts to create commercially viable LEDs for lighting markets found customers among flashlight manufacturers and a handful of other, specialist applications. The LED story though is one of continuous innovation in LED technology, and since the turn of the century, innovation has led to a complete transformation: the white LED has become the lighting industry’s mainstream light source.

So does that mean it’s job done? Far from it – the innovation in LED technology continues. In many ways, we have only just begun.

 

Lighting as a configurable ambient optical environment

The first 20 years of LED development were largely concerned with enhancing the quality and consistency of the light output, and with increasing brightness and efficacy. Recently, however, the LED industry has turned its attention to new, exciting possibilities in the control and configuration of lighting. As a semiconductor product, the LED is inherently compatible with digital control technologies. And this opens up new potential for lighting designers and architects to create never-before-possible effects with LED light sources.

An early view of the potential emerged with the development of ‘dim-to-warm’ products, an application of tunable white lighting. These advanced dimming products enabled the independent control of color and intensity, giving the designer two separate levers to pull. By contrast, incandescent and halogen have only has just a single lever – dimming the light automatically produces a color shift to a warmer CCT – there are no options.

This sparked a new burst of innovation in the manipulation of light, leading to today’s pioneering implementations of human-centric lighting and dynamic white lighting. Some are focused on aligning artificial lighting with people’s circadian rhythm. Others are exploiting the power of lighting to promote attentiveness, combat fatigue, induce restfulness, or to generate other emotional or physiological responses on demand. With dynamic white lighting, CCT values, intensity and even the spectral content of light can be adjusted to suit the task or time of day.

Lumileds innovations are helping forward-thinking lighting designers and specifiers to accelerate this shift from a static to a dynamic model of lighting operation. One example of this is the LUXEON Fusion technology, which enables the next step in human-centric lighting, providing the option to adjust light levels throughout the day to complement a changing ambient environment. The easy approach is to simply use a range of white LEDs. Lumileds researchers though realized that by using different colors from within the visible color space would allow for a better spectral performance, efficiency, and consistent light output over the dynamic white range. This type of innovation, only possible with solid-state technology today, gives us better solutions that do more than simply replicate what previous technologies were capable of.

In this dynamic or configurable model of lighting, the choice of light source substantially affects the outcome. If your goal is to offer healthful, manageable, full-spectrum illumination, it makes no sense to start with a light source which provides a limited range of CCT values, or has a poorly balanced spectral power distribution, or produces limited light output over the color range. It’s difficult and expensive, and involves inflexible engineering work-arounds, to bolt consistent, accurate full-spectrum color control on to a two-channel array of basic warm- and cool-white LEDs.

The need for light sources optimized for new types of dynamic lighting is driving innovation in LEDs in new directions. Products such as LUXEON Fusion are testament to Lumileds’ commitment to this next wave of innovation. And thanks to the investments in semiconductor, phosphor and optical technologies by Lumileds and others, there will be much more in this vein in future.

Watch this space.