3D Printers

Terahertz lenses change our view of the world?

Northwestern Engineering has harnessed the power of 3D printing to create a new kind of lens that works with terahertz waves.

 

It’s a form of electromagnetic radiation that sits between infrared light and microwaves in what is conveniently known as the terahertz gap. It shares a number of properties with both of them.

 

Untapped potential abounds in the spectrum

There’s apparently a great deal of untapped potential in this spectrum. Technically, if we can exploit terahertz technology then we could have better imaging. That is just the start.

 

Most modern lenses have a number of elements, or at least a number of components within each lens, to compensate for inherent problems. Expensive lenses for Single Lens Reflex cameras, for instance, often have a number of lenses in one barrel to achieve their stellar results. This adds to the complexity, cost and weight of the lens, which is obviously dwarfed by modern telescopes.

 

An index shift

Current lenses rely on precise curvature and refractive index, while the new lenses use a gradient index. This means that one lens can take the place of several and they do not require any level of correction. This could change photography forever, but also has a number of other applications.

 

Terahertz lenses can be used in security scanners to detect concealed weapons and even plastics and chemicals. Terahertz radiation, also known as submillimetre radiation, is also completely harmless, so it is much safer than an X-ray. Inevitably that means the lens has medical uses.

 

So it is really technology that could have a significant impact on all of our lives.

 

3D printing has opened up a new spectrum

But why, then, are we just hearing about these lenses now? Well the discovery of a metamaterial that has no ready equivalent in the natural world is one reason. It is made up of structures that are smaller than the terahertz wavelength.

 

This has allowed the team of scientists led by Dr Cheng Sun to experiment with the potential of the wavelength and even harness it for the first time with a controlled gradient index that simply wasn’t possible with traditional materials.

Dr ChengSun.jpg

3D printing plays a part in this as well. Now the industry has got past the issues associated with lens production, which did hamper its progress for some time, it now affords the manufacturers a vast amount of control they simply didn’t have before.

 

Projection micro-stereolithography is the technical term for the printing process employed to devastating effect in these lenses. This allowed researchers to create the highly specialised lenses that can handle the frequencies of terahertz waves.

 

The good news is that it is a production process that is scalable. So mass production of a product we simply couldn’t dream about before is now a question of when, not if.

 

The hard work starts now

 

The National Science Foundation supported the research that was published on April 22nd. There’s some advanced Physics at work here, but the end result could be a completely new kind of lens system for everything from our mobile phones to hospital scanners.

 

3D printing has once again opened doors that left traditional manufacturing techniques firmly out in the cold. Only now can we truly start to experiment and understand the potential of terahertz radiation, so we can’t tell you what the future holds.

 

We can say, though, that the scientific community is seriously excited. Perhaps we should be too.