When I think of an ultra-powerful laser, I usually get an image of Goldfinger about to slice James Bond in two. But some lasers can actually be used to look under your skin without causing any damage, providing a new non-invasive way to diagnose medical issues.
Terahertz nondestructive evaluation (NDE) allows doctors to inspect something like a tumor without making an incision, and with more detail than a traditional x-ray or MRI. It also has non-medical uses, such as inspecting suspicious bags and packages without opening them. NASA's even used terahertz NDE to check for problems like tiny cracks in rocket parts.
Until recently, the far-infrared lasers needed to do this type of evaluation have been huge and unwieldy, requiring helium cooling systems and massive magnetic fields. That's not exactly the kind of rig you can put in your typical airport security line. So the race has been on to develop a solid state version that's sufficiently powerful enough to do the job.
The latest breakthrough has come from the University of Leeds in England, where researchers at the School of Electronic and Electrical Engineering just announced that they have broken the one watt barrier. That may not sound like a lot, but apparently when you're talking about far-infrared lasers, that's huge. It beats a team from Vienna who developed a half watt version last year, and one from MIT that broke the quarter watt barrier before that.
When this will actually turn into something in your doctor's office or that the TSA will want isn't clear, but I'd say you should probably become concerned if a TSA agent suddenly tries to strap you down on an inspection table.