Lighting is so much more than illumination. Visible light is replacing chlorine, radio waves, electricity, and even medications.
By David Shiller
What do visible light disinfection, LiFi, fiber optic communications, quantum computing, and medical light therapies have in common? They are all examples of light replacing older technologies, often with enormous benefits. We can call this macro-trend the Lightification of Things. Let’s look closer at the examples.
Lighting as Disinfectant
There has been a lot of trade press (including the pages of enLIGHTenment Magazine) about visible light disinfection. This technology uses a special wavelength (color) of violet light (often 405 nm) to disinfect surfaces exposed to the light.
The technology is catching on in the healthcare industry, where infection prevention is of life-and-death importance. In many cases, ceiling fixtures will produce both white light and the special wavelength of violet to simultaneously light the room and gradually disinfect. The specific wavelength of violet light has been demonstrated to kill bacteria, including nasty ones like MRSA and C. diff. The violet light triggers chemical reactions within the bacteria that kills them. In this case, visible light is able to do a job that once required chlorine bleach or UV light — both of which have safety issues. Visible light disinfection still requires traditional cleaning, but improves the results.
A New Transmitter
Most people use WiFi every day. WiFi is a radio that connects our phones, tablets, computers and – in the IoT dream – every electrical device imaginable to the internet. The WiFi router transmits and receives the radio signals in a home or business and typically has a hard-wired connection to the internet service provider, often a cable or telephone company.
LiFi is an emerging technology that uses visible light instead of radio waves to transmit the data to and from our devices. The lighting fixture acts as a router, and the light is flickered at a frequency much too fast for our brains to perceive; that flickering carries the data. Here are some of LiFi’s advantages:
Greater security in that the light doesn’t leave the room and neither does the data — unlike WiFi, which travels through walls and can be more easily intercepted.
Much faster data rates. LED LiFi can transmit roughly 10 times the data per second than WiFi, and laser LiFi can transmit roughly 100 times more data per second than WiFi. The IoT is rapidly increasing the data load on routers and many believe WiFi data rate capabilities will soon be exceeded. LiFi may solve this need for much higher data rates.
Reduced human exposure to radio waves. Some countries in Europe are beginning to replace WiFi in schools with LiFi over concerns that WiFi can create potential health problems in children. In this case, white light can replace radio signals, or augment WiFi based on its advantages.
Can It Replace Electricity?
For many of us, the WiFi router in our home is connected by a cable to the internet service provider (ISP), which uses fiber optic cables to bring internet service all across a city. Fios by Verizon is a well-known example. Lasers are used in a fiber-optic network to transmit data through the optical cables. In this case, laser light is replacing electrical wires to transmit more data, much faster, both to and from the home or business.
A different property of light is being researched to replace electricity in computer processing chips. At a fundamental level, light is composed of photons. Photons can have different polarizations that can be thought of as an orientation of the planar wave nature of light. Photons are described as having left or right circular polarization, or a combination of the two. If it’s both polarizations, it is known as “superposition.” The left, right, or both, can be thought of as 0, 1, or both. This is the foundation of the “Qubit,” the fundamental unit of data in a quantum computer. By contrast, our current computers use the on and off of electrical circuits to represent the 0 and 1 of a “bit” of data. This is why we measure data and network speed in kilobits, megabits, gigabits, etc.
In a quantum computer processing chip, Qubits of light/photons store and represent data. The 0, 1, or both, for each Qubit is then processed using algorithms analogous to conventional computers processing bits (0s or 1s). However, the “both” state of qubits gives quantum computing an exponentially larger computing power.
The bottom line is that quantum computers use photons of light instead of electricity to define the basic units of data (qubits instead of bits). Quantum computers are probably about 10 years away, but progress is being made every year by companies such as Intel, IBM, Microsoft, Google, and others.
Alternative to Drugs?
It’s hard not to come across articles about circadian lighting these days. The idea is that light intensity at the eye, spectral content, duration, time of day, and a person’s age combine to impact their circadian system, sleep, and overall health.
This is just one aspect of light and health, however. Many researchers around the world are studying other non-circadian ways that light can be used to directly treat a long list of health concerns, including: migraines, chronic depression, chronic ulcers, hair loss, constipation, acne, pain relief, high blood pressure, PTSD, and sensory-processing disorders. The field of light therapy is likely to grow very quickly and can potentially replace many medications, thereby avoiding the undesirable side effects of pharmaceuticals.
In all of the cases above, light is being used to replace older technologies. Lightification often comes with tremendous improvements in performance, such as LiFi’s order of magnitude better data rates, or quantum computers’ exponentially higher computing power. As our knowledge and capabilities with light advance, expect to see light used to replace more types of traditional technology.