University of Bristol Demonstrates Quantum-Inspired Noise Reduction in Laser Sensing

Researchers at the University of Bristol have demonstrated a new laser range-finding technique achieving sub-millimetre accuracy in distance measurements, even under challenging daylight conditions. Published in Nature Communications, the team’s work translates principles of quantum sensing into a practical laser system capable of operating in real-world environments, a feat previously hindered by disruptive noise from sunlight and atmospheric interference. The system successfully measured the distance between the Queens Building and the Wills Memorial Building, approximately 155 metres, with accuracy exceeding 0.1 millimetres, utilizing laser power comparable to a standard laser pointer and completing measurements in just one-tenth of a second. “This work addresses a long-standing question in quantum sensing – whether the advantages seen in quantum experiments can be reproduced using more practical technologies,” said Dr Weije Nie, Research Fellow, and Professor John Rarity, in the School of Electrical, Electronic and Mechanical Engineering. This advance promises improvements for applications ranging from autonomous vehicles to space exploration. Energy-Time Entanglement Inspires Classical Laser Noise Reduction Instead of relying on actual quantum light, the researchers recreated the key noise-resistant characteristics of energy-time entanglement within a conventional laser setup, utilizing optical fibres and electronic modulators to rapidly alter the colour of laser pulses. This innovative approach generates signals with engineered correlations that mimic the behaviour of quantum signals when filtering out background interference, and these signals are millions of times brighter than typical quantum light sources. Further validation involved measurements between the Queens Building and Cabot Tower, exceeding 400 metres, again in full daylight and varying weather, confirming the system’s reliability outside of laboratory conditions. Co-author Dr Alex Clark added that the University has a long history of breakthroughs in quantum science and technology, and it was fitting that they were able to test their new technique using some of its most historic buildings. The team intends to expand the system’s range and reduce its size through the integration of photonic devices, allowing for broader deployment. The pursuit of precise distance measurement has long been hampered by environmental interference, limiting the effectiveness of optical sensing technologies in real-world scenarios; existing systems often struggle with the disruptive effects of sunlight and atmospheric conditions, particularly at greater distances. This limitation impacts applications requiring high precision, such as surveying, mapping, and robotics. This work addresses a long-standing question in quantum sensing – whether the advantages seen in quantum experiments can be reproduced using more practical technologies. Source: https://www.bristol.ac.uk/news/2026/march/quantum-inspired-laser-system-delivers-distance-measurements.html DISTANCE MEASUREMENT LASER SYSTEMS OPTICAL SENSING QUANTUM SENSING UNIVERSITY OF BRISTOL