SSL will find use beyond general lighting as LEDs control the electromagnetic spectrum (MAGAZINE)

Oct. 20, 2012
Adaptive lighting controls will improve our health and wellbeing, and SSL will add communications capabilities as new LED-based products control the electromagnetic spectrum in real time, explains Next Lighting CTO Steve Paolini.

This article was published in the October 2012 issue of LEDs Magazine.

View the Table of Contents and download the PDF file of the complete October 2012 issue, or view the E-zine version in your browser.


One way to take the pulse of solid-state lighting (SSL) is by regularly purchasing LED replacement lamps. With installed sockets in the billions, it’s hard for the newcomers to resist a run at this market even if it’s not the best way to utilize LED technology. The quality and performance of the better SSL products now on the market often exceed the vacuum incumbents, so it would seem only price remains as the final hurdle to clear on the way to the finish line. But is the finish line mass replacement of vacuum lighting with SSL? If history is a guide, there is less a finish line and more of a journey to be taken.

Transistors did not stop developing once they successfully replaced vacuum tubes in radios, amplifiers, and switching gear and neither will LEDs finish with lamp replacement. Imagining these next steps is no guarantee it’s what will be, but it’s a necessary step. With the L Prize lamp and other quality replacements on the market we can now give some serious thought to and seriously work on what lighting could really be with this new technology.

One of the fundamental values of LEDs is they allow us to control an important part of the electromagnetic spectrum. It’s not only important because our eyes need it to see, but most everything that lives on the planet is profoundly affected by it.

One type of electric illumination I’d like to have is the light that comes through the window on a nice day. The gradual change in intensity and spectrum that occurs throughout the day would be great to experience at will. Natural light has spectral, temporal, and spatial components that not only illuminate, but subliminally stimulate and satiate our well being.

The night brings light from the moon, candles, and the aurora borealis that could be enjoyable to call up on demand. Once the capability to manipulate the spectrum in real-time is included in SSL, the sky is the limit as to the type of illumination we can have, perhaps similar to the vast music and video catalogs that exist today.

Beyond spectrum and time, there is the distribution and direction of the illumination. SSL could be made to replicate the collimated rays of the whitish sun moving across the southern sky, while the diffuse bluish light of the northern sky changes in hue and intensity throughout the day.

These attributes are not just enjoyable – they have circadian health, student learning, and employee productivity implications. While SSL must become less expensive to be widely adopted, even small improvements in health and productivity have significant positive economic payback.

In addition, the electromagnetic spectrum can be used for telecommunications and as our consumption of bandwidth continues to increase there is little doubt this portion of the spectrum will see double duty. Unlike radio waves, light waves don’t travel through walls, but this can be a good thing depending on the application. Communications are more secure and bandwidth can be completely reused in the next room. As more colors of LEDs are used to manipulate the spectrum for lighting they also increase the number of communication channels in a given fixture.

One startup in the Boston area has developed a local positioning system that piggy-backs on an SSL installation. Used in conjunction with a cell phone camera and app, it can place your exact location inside a building and give directions to any other place in the building. For example, a man looking for dress shirts in a department store could point his phone camera toward the lights and enter a query that directs him to shirts. Even slightly higher turnover in the store, or less time for the customer to find something, translates into economic value.

In the short term, the focus is on replacement lamps. Examining them carefully can provide valuable insight into performance improvements and cost reductions. However, there is more to SSL than lower price, less energy, and longer life. Just around the bend are wonderful new lighting products and services just waiting for the market to ask for or perhaps the next Steve Jobs to show us what we could really have.