Exclusive | 'Father of LiFi' Professor Harald Haas Explains How Light Can Transmit Data Faster Than WiFi

By Surabhi Gupta

New Delhi: Imagine a world where every bulb in your room doesn’t just illuminate but also connects you to the internet. This isn't some imaginary future but a breakthrough technology that is right around the corner, LiFi, or Light Fidelity, which transmits data using light waves instead of radio waves.

At the India Mobile Congress (IMC) 2025, Professor Harald Haas, the Director of the LiFi Research and Development Centre based at the University of Cambridge, in an exclusive interview with ETV Bharat, shared details about how LiFi technology operates, some of the benefits of LiFi over WiFi, and its potential impact on the future of global communication.

Recognised as the Father of LiFi, Haas said, "LiFi is wireless communication with light," and suggested that the world could be using it very soon. "We use visible light, infrared, or even ultraviolet light to transmit data at very high speeds. The concept is to take any light, any light transmitter, any light bulb in your room, to use it as a high-speed Wi-Fi access point."

In contrast to WiFi, which depends on congested radio frequencies, LiFi transmits data using light emitted from LED bulbs. These bulbs flicker at incredibly fast speeds—millions of times per second, encoding digital data within the pulses. The flickering is imperceptible to the human eye but readable by LiFi receivers, which convert the signals back into electronic data.

“The light pulses are like Morse code, rapid flashes of brightness that represent binary code,” Professor Haas explained. “Your device's receiver picks up these changes and converts them into data streams. It's simple physics, but done at a scale to unlock completely different potential.

The science of data transfer via light

With a typical LiFi system, an LED bulb connected to a LiFi router modulates the light signal. These signals are received by a photodiode or optical sensor attached to a device. Since the visible light spectrum is 10,000 times broader than the radio spectrum, LiFi can achieve data rates that are exponentially higher.

A 2017 study by the University of Eindhoven demonstrated download speeds of 42.8 Gbit/s using infrared light within a 2.5-metre radius. In theory, LiFi could even reach speeds close to 224 Gbit/s, meaning a 1.5 GB film could be downloaded in milliseconds.

Haas added, “Our current research focuses on achieving terabit-per-second aggregate data rates in a room from a single light source. We’ve done numerous experiments and have even spun out a company, pureLiFi, in the United Kingdom to bring these products to market. They are already being tested in hospitals, schools, and industrial environments.”

Why LiFi is more secure than WiFi

One of LiFi’s most striking advantages is security. Because light cannot pass through walls, the signals remain confined to a single room, making it nearly impossible for intruders to intercept data.

“You touch on a very important aspect, security,” said Haas. “Light doesn’t go through walls. Even with windows, it’s almost impossible to extract signals from outside. You would need very precise optics on the other side, positioned perfectly, to capture even a fraction of the signal. This makes LiFi naturally private and extremely secure.”

This feature makes LiFi ideal for use in defence establishments, government offices, hospitals, and financial institutions, where data protection is paramount. It also eliminates electromagnetic interference, which can disrupt sensitive equipment in hospitals or aeroplanes.

He added, “Securing sensitive data, whether it’s critical to national security, protecting intellectual property, and company data, is becoming increasingly challenging for both governments and enterprises. Kitefin XE will enable wireless communication in previously impossible scenarios and revolutionise the way companies deploy connectivity, providing confidence and protection in this evolving security landscape.”

LiFi vs WiFi: Who wears the wireless crown?

Although WiFi is the more common wireless standard today, LiFi is a newer, more sustainable option. Not only in terms of speed and security, LiFi also permits more devices to connect with more stability, as it can transmit 10,000 times more bandwidth than radio waves and is not impacted by electromagnetic interference—unlike WiFi, which can conflict with any radio device. Regarding cost and sustainability, LiFi is up to 10 times cheaper to build a system, with fewer parts and less energy use, since LiFi works with the LED lights we already use.

“LiFi pairs beautifully with 6G”, said Professor Haas. “6G is about networks that we are creating that will be fast, resilient, and carbon-neutral. LiFi has all of these aspects, and it will make your networks even better, faster, and greener".

Lighting the way to a carbon-neutral future

Haas emphasised that LiFi’s evolution aligns with the world’s push for sustainable, energy-efficient technologies. “When you think about zero-energy or carbon-neutral communication, LiFi fits naturally,” he said. “The same LED that provides illumination can transmit data. You don’t need a separate router or energy source, just light.”

He envisions a future where holographic displays, AR/VR applications, and ultra-HD streaming on smartphones will rely on light-based communication. “For technologies like holographic 3D displays, you need data rates in the tens or hundreds of gigabits per second. The radio spectrum simply can’t handle that. But visible light can.”

From airports to aircraft: Real-world applications of LiFi

LiFi is already being piloted in several sectors worldwide. Offices are integrating LiFi-enabled luminaires for high-speed internal communication. The aeronautical industry is exploring it for in-flight data systems, while airports, hospitals, and city infrastructure are testing LiFi to manage large user volumes securely.

According to a Global Market Analysis (2018–2028), the LiFi industry is projected to reach $36 billion by 2028, growing at an astonishing CAGR of 71.2 per cent. The Asia-Pacific region, led by India, is expected to dominate adoption and innovation.

Challenges and the road ahead

Like any emerging technology, LiFi has hurdles to overcome. Its biggest limitation is the line-of-sight requirement; data cannot be transmitted if the receiver is out of the light’s range or if the light is blocked. However, researchers are developing hybrid systems that seamlessly switch between LiFi and WiFi to ensure uninterrupted connectivity.

“Challenges are part of innovation,” Haas noted. “When WiFi was invented, people said it wouldn’t scale. Today, it’s everywhere. LiFi is at a similar stage. Once we integrate it with everyday lighting and devices, the possibilities are limitless.”

Haas added, “Connectivity defines how societies evolve. With LiFi, we’re expanding that connectivity into the optical domain, into light. It’s faster, safer, greener, and limitless. The future is bright, literally.”

Indian digital ecosystem

Visibly impressed with India’s expanding digital ecosystem, Professor Haas praised the scale of the India Mobile Congress and expressed enthusiasm about collaborating with Indian researchers.

“I’ve just arrived from the UK, and what I’ve seen here is really amazing,” he said. “The industry is huge, and the energy is palpable. India is going through a transformation, and connectivity is the nervous system of a modern society. That’s what India is trying to establish. You need not just fibre connectivity, but also room-level connectivity, massive data networks, and efficient communication systems for future industries.”

Haas also revealed ongoing collaborations with IITs and Indian research institutions, emphasising the importance of nurturing talent and innovation around LiFi technology.

“I would be absolutely delighted to collaborate with Indian researchers and commercialise LiFi here,” he added. “There’s so much potential and technical talent in this country, it’s inspiring.”