The future of lighting is lasers
If we switch to laser lighting, it could transform our homes and even yield glow in the dark curtains. Chris Smith caught up with Steve DenBaars to find out more...
Steve - You could imagine you could have one blue light source per house and, rather than run your light around with copper wires, you could route the light with plastic or glass fibre optics through the rest of the house and then convert it to white light whenever you need it. And, therefore, you could drop a lot of the cabling needed for lighting but you could also imagine a very different looking lighting fixtures. You don’t need big bulky metal fixtures anymore, you would need very small sources or you could even think about weaving fabric into the curtains or the ceiling to get a distributed effect.
Chris - So we’re talking about the death of Edison's dream really aren’t we? We’re saying this is the end of the light bulb as we know it - we don’t need that technology anymore. We just need to build fixtures and fittings that could take a fibre optic input, driven by a laser which could be hundreds of feet away elsewhere in the building and the light arrives in a tube called a fibre optic, goes into that surface, and the whole wall or the whole ceiling or, even as you say, your curtains glow and that illuminates the room.
Steve - Yeah, that’s right. We think this gives the designer a lot of freedom. But I will point out you can actually see laser lighting today already in Europe. It turns out that BMW and Audi have already released a high-end automobiles with laser headlights because it’s so bright and efficient at directed light as well. I think there’s more than a thousand cars already on the roads in Europe using this laser lighting technology.
Chris - Why do you think that running fibre optics round your house and bringing the light in as light rather than electricity in a copper wire is better?
Steve - Yeah, that’s a good point. The fibre optic cable could be extremely small - we’re talking here less than a millimetre. So you don’t need to waste a lot of copper material which, as you know, is expensive but also you could potentially get an electrical shock. So it just lets you make lighting fixtures that are much smaller. In existing buildings, they allocate almost a foot for all this cabling and fixturing. I mainly think is a way to just not only design cool fixtures but save on the cabling, materials cost, and metals associated with that as well.
Chris - With an eye on the whole concept of the internet of things, we talked in a recent edition of the Naked Scientists about the concept of li-fi (your connection to the internet being by visual signals from light bulbs), could you use this as an extension of that? Could people connect to the internet, download data by their wall flashing imperceptibly at them?
Steve - Well, I’m impressed, because you already made the connection that we’ve been working on research only for two years in a hard way that is. I think there’s been some work in the UK. I think Professor Harold Hoss has been doing li-fi with LEDs, but we can do the same thing with laser lighting. In fact, we’ve already done that and we’ve demonstrated communication speeds more than 100 times faster than you can do with the traditional LED li-fi bulbs you have in the store, that is. We are able to transmit 5gb per second. So just to give you some sense, that is getting up into the same speed you’d use in a fibre optic cable.
Chris - Is this safe, Steve? If I’ve got fibre optics running around my property and they’re full of extremely intense coherent blue laser light, if I were to accidentally chop that into that, now I wouldn’t get an electric shock, but I could blind myself couldn’t I?
Steve - Yes, so we really need to develop failsafe optical systems and sensors. On a very high level, I’ll just tell you some of the safety schemes we are working on is that if the cable is cut, within nanoseconds the cable is able to sense that it’s actually been cut and it immediately shuts off the laser.
Chris - How long is it going to be, do you think, before it’s de rigueur to walk into your lounge and you will flick on a switch which won’t activate a light bulb in a ceiling, it will make the ceiling glow and the curtains illuminate?
Steve - It’s going to take a decade, I think, to really make laser lighting commonplace. However, it’s already showing up in automotive lighting and even in cinema displays in Asia.
Chris - Well, that’s interesting isn’t it? So, if your internet connection comes through your sofa, does that make you a couch surfer I wonder?
That was Steve DenBaars from the University of California, Santa Barbara, thank you very much and thank you to him.
Also with us this week is Colin Humphreys. Do you fancy the idea of curtains illuminating your room from a laser source colin - what do you think?
Colin - You could have a whole wall of illumination in the room which might be interesting and we can, in fact, use an LED to do this as well. So a laser may be slightly more powerful but the LEDS you can use. In fact, in museums, they’re using this to illuminate cabinets so you don’t the fibres coming and they’re LEDs on the end.
Chris - Graihagh, do you like the idea of a sofa that illuminates the room?
Graihagh - I just can’t really imagine it. That or a glow in the dark curtain. I don’t really see the attraction in that rather than just having a regular light. What is the attraction?
Chris - I think the point is we design rooms at the moment with light sources being in the ceiling in a central point. You get dark shadowy corners and it’s dictating how room are formatted and if you actually had a light coming from all different kinds of places, it would allow designers a lot more freedom.
Graihagh - I suppose it might seem quite more natural as well.
Chris - It could do because it would mean that the room didn’t have dark corners anymore.