https://www.unsw.edu.au/newsroom/news/2026/03/New-negative-light-technology-hides-data-transfers-in-plain-sight UNSW Logo UNSW Newsroom logo * Study Study options + Explore degrees + Short courses + Online + Our faculties Discover UNSW + Undergraduate study + Postgraduate study + International students + Higher Degree Research + Our campus + Accommodation + Support for students How to apply + Domestic undergraduate + Domestic postgraduate + International + Higher Degree Research + Fees + Scholarships Help centre + Ask a question + Speak to a student + Received an offer? + Information for parents + Information for educators + Agent Hub Apply now Connect with us * Research Research strengths + Clean energy + Climate adaptation & built environment + Technology for good + Healthier lifespans + Equity, security & prosperity Partner with us + Research & development + Grant funding + Case studies + Investment portfolio + Unisearch expert opinion + TORCH Facilities & infrastructure + Find a facility + Find an instrument + Mark Wainwright Analytical Centre + Research Imaging NSW + Research Technology Services Higher degree research + Find a Supervisor or Project + Scholarships + Application process + Fees and costs + Industry engagement + International engagement opportunities Contact us Find a researcher * Faculties Our faculties + Arts, Design & Architecture + Business School + Engineering + Law & Justice + Medicine & Health + Science + UNSW Canberra * Engage with us Engage with UNSW + Social media + Community outreach + Complaints Giving + Overview + See the impact + Why give to UNSW + Areas to support + Give now Alumni + Overview + News & events + Benefits & services + Ways to get involved + Update your details Find an expert + Find an expert Industry partnerships + Partner with us + Services and solutions + Funding opportunities + Small businesses + Impact and case studies * About us Our story + Leadership & governance + Our strategy + Our culture + Our people Our impact + Social impact + Innovation + Enterprise + Centres & institutes Collaboration + Community + Industry + Government Our campus + Faculties & Schools + Respect & diversity + Library Excellence + Education + Research + Human resources * News * Events * myUNSW * Alumni & Giving * Envelope icon Contact Us UNSW Logo [unsw_newsr] Type in a search term [ ] * Search Advanced search * Search news * Find an expert * Annual reports * Contact Follow Follow * Follow UNSW on LinkedIn * Follow UNSW on Instagram * Follow UNSW on Facebook * Follow UNSW on WeChat * Follow UNSW on TikTok * WhatsApp New 'negative light' technology hides data transfers in plain sight 2026-03-09T09:43:00+11:00 Electromagnetic waves background The new process 'hides' data within natural heat radiation, such as can be seen with a thermal camera. Adobe Stock Expand social share Close social share Neil Martin Neil Martin, Researchers have developed a 'negative luminescence' system to create an innovative way of sending hidden information. Engineers at UNSW Sydney and Monash have developed an innovative way of sending hidden information that's hard to intercept. Using a phenomenon known as 'negative luminescence', the system works by making signals blend perfectly into the background of natural heat radiation, such as can be seen with a thermal camera. To outside observers, it looks like no data is being sent at all. Only a receiver with the right equipment can pick up the hidden message. Because the very act of communication is invisible, the method makes signals almost impossible to intercept or hack. That means it could one day offer a powerful new security tool for sensitive communications in fields like defence and finance. Media enquiries For enquiries about this story and interview requests please contact Neil Martin, News & Content Coordinator. Email: n.martin@unsw.edu.au --------------------------------------------------------------------- Ned Ekins-Daukes Michael Nielsen Featured experts Ned Ekins-Daukes, Michael Nielsen, Electromagnetic waves background The research team have developed a way to send signals which blend perfectly into the background of natural heat radiation. Adobe Stock, VicenSanh The research team, led by UNSW Professor Ned Ekins-Daukes and Dr Michael Nielsen, and including Professors Michael Fuhrer and Stefan Maier from Monash University and Imperial College London, have so far managed to send data at about 100 kilobytes per second in lab experiments. But they believe speeds could reach gigabytes or even faster with further improvements to the emitter technology. "Data is so ubiquitous nowadays, but we're not necessarily coming up with new ways to protect that data," said Dr Michael Nielsen, lead author from UNSW's School of Photovoltaic and Renewable Energy Engineering. "We do have encryption methods, but at the same time we're always having to create new encryption methodologies when bad actors find new decryption strategies. "But if someone doesn't even know the data is being transferred, then it's really very hard for them to hack into it. If you can send information secretly then it definitely helps to prevent it being acquired by people you don't want to access it." The new process, described in a paper published in Nature Publishing Group's Light Science and Applications, utilises the special effect of negative luminescence from LEDs operating in the mid-infrared part of the light spectrum. Everything gives off a faint glow of heat in the infrared, which we normally can't see - unless using special thermal cameras. Negative light "What makes negative luminescence so interesting is that it makes that glow look darker instead of brighter. By way of a comparison, it would be like a flashlight that can somehow go darker than 'off'," added Dr Nielsen. "While that's not possible to achieve with visible light, certain materials can create this 'negative light' effect in infrared, which is what the research team are now exploiting. "In traditional data communication, information is transferred by something being either on or off. That can be as basic as a flashing light, or radio waves, or signals sent down optical fibres. "Observers are able to see that data is being transmitted, even if they cannot read the message because of it being encrypted in some way. "But with negative luminescence it is possible to create a hidden signal using a special device called a thermoradiative diode." The diode can switch output quickly between brighter and darker-than-usual states which creates a pattern that blends into the usual background 'noise' and is therefore invisible to anyone not aware that data is being sent. The hidden information transmitted by such thermoradiative diodes can also be encrypted in traditional ways, adding yet another level of security. A semiconductor device called a thermoradiative diode that is able to generate power from the emission of infrared light. A thermoradiative diode which is able to transmit hidden data. UNSW Sydney Thermoradiative diodes The use of thermoradiative diodes in such a way was inspired by Prof. Ekins-Daukes and his UNSW colleagues' previous innovative work in producing so-called 'night-time solar' - electricity created from solar power even when the sun has set. "We technically call this new process thermoradiative signatureless communication. As part of our work on the night-time solar project we determined that the negative luminescent property was critical to how good our thermoradiative diodes performed," said Prof. Ekins-Daukes. "Today we have demonstrated a thermoraditive surface that can be modulated such that the signal is transmitted in all directions. Future iterations of the technology can make it directional and in the longer-term, guided in a way similar to fibre communications." The team are confident the data transfer speeds will increase dramatically over the proof-of-concept device reported. "A commercial product delivering megabit data rates can be envisioned within a few years of development. Here in Sydney we have the semiconductor equipment we need to produce the next-generation prototypes of this device at the Australian National Fabrication Facility on the UNSW campus," said Prof. Ekins-Daukes. "For this research we have been working with mercury cadmium telluride, but we are actively exploring less toxic antimonide-based semiconductors. "Our colleagues at Monash University have already proposed that if we could use graphene - which is a very conductive material made up of a single layer of carbon atoms arranged like a honeycomb - then we can potentially achieve data transfer rates in the gigabytes per second range, if not hundreds of gigabytes." Share this story * Share this page on Email * Share this page on Facebook * Share this page on Twitter * Share this page on LinkedIn * Share this page on WhatsApp * Share this page on FacebookMessenger * Share this page on WeChat * Share this page on Copy --------------------------------------------------------------------- Related stories * A semiconductor device called a thermoradiative diode that is able to generate power from the emission of infrared light. 'Night-time solar' technology can now deliver power in the dark * Photo: Mel Koutchavlis UNSW celebrates seven finalists in the 2025 Eureka Prizes * CHICAGO - SEPTEMBER 01: Solar photovoltaic panels generate electricity at an Exelon solar power facility on September 1, 2010 in Chicago, Illinois. The 10-megawatt facility located on the city's south side is the largest urban solar installation in the United States. The 32,292 panels can generate more than 14,000 megawatt-hours of electricity per year, enough to meet the annual energy requirements of up to 1,500 homes. 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