17. October 2017
Without fiber optics, the internet as we know it would be slow and dull. This page would probably still be loading, watching a movie would still involve a trip to the video store, and you would still be paying for long distance telephone calls.
As essential as fiber optic technology is for the world’s communications, this glass-based technology is breaking new ground, particularly in fiber optic imaging, where it keeps soldiers safe, helps doctors find and fight disease, and lets technicians peer into hot, cramped spaces that normal imaging systems could not go.
In fact, the rise of fiber optics in telecommunications over its use in imaging systems is something of an irony. The invention of fiber optics dates back to the 1950s, when the U.S. military began experimenting with it as a way to convey encrypted images. That didn’t work out – the messages were too easy to crack – but engineers and inventors took the technology and, over the decades, built the networked world we live in now.
Many optical engineers find this surprising, but it’s true. Fiber optics have distinct properties that make them ideal for several imaging applications, and their use is now catching up to the telecom world.
Fiber optics used in imaging applications come in both flexible and fused formats. Flexible bundles can peer around corners and travel tight paths. Fused bundles are stiff, but capable of withstanding high heat and harsh conditions. Fused fiber optic plates improve the resolution in imaging systems.
No metal, no magnets
Both flexible and fused fiber-optic systems have two distinct advantages over other formats. They are non-metallic, and therefore non-magnetic, and they are also passive, meaning they don’t need electricity.
Fiber optics are key components of magnetic resonance imaging systems, or MRIs. These machines rely on magnets and radio waves to take non-invasive pictures of the insides of bodies. The use of powerful magnets, however, means that MRI machines are very sensitive to the presence of metal – which is why MRI technicians ask several times if patients have any metal in or on them.
Fiber optic components transmit light and images to the technician. They are made of glass or plastic, with a flexible plastic housing. In a wound or leached bundle, even the end tips can be made of plastic. There’s no metal involved.
Passive doesn’t mean useless
The fiber optics used in MRI machines also need to be passive; that is, they need to work without electricity. Electrical currents would interfere with the magnet’s coil.
That passive quality also has applications in the military, where it can be used if a vehicle suffers an electronics failure and can’t use its primary targeting or guidance systems. That’s where backups come in. A passive optical system doesn’t need electricity, so it can be used in place of the primary. Armored troop carriers also use these components to view areas close to the vehicle in situations where windows would defeat the purpose of armored plates.
And because these systems are made of flexible fiber, they can be retrofitted into existing systems. New FAA regulations, for example, say that pilots in the cabin must have a way to see out of the cockpit door, and even outside of the plane in case of emergency.
But fiber optic material doesn’t have to be flexible to be useful.
Rigidity has its place
Rigid plates of fused fiber optic material, baked into a “loaf’ and sliced to make faceplates, are rising in popularity. Fiber optic faceplates have been used in all three generations of night-vision goggles. In Industrial monitoring systems at power plants, fused fiber optic cables can examine very hot boilers for signs of inefficiency that increase air pollution.
Fiber optic faceplates are also used in digital X-rays, allowing dentists, surgeons, and doctors to see crisper images by reducing noise and improving resolution.
Defined-angle viewing faceplates can be integrated into cell phones and other devices to make them more secure. These devices prevent the unauthorized dissemination of sensitive information by ensuring information on a screen is only visible when a user is looking directly at it. At sharp angles, the screen appears black.
A growing list of applications
Fiber optic components for image transfer have been used in military, commercial, and scientific applications. New uses for this technology are being found every day as optical engineers discover the benefits of a flexible, non-magnetic, and electricity-free imaging components.
It is a material that merits consideration in almost any new imaging process.