LIDAR Breakthrough Overcomes Range Limitations
LIDAR technology’s breakthrough provides greater sensitivity and precision in measuring remote object distance, published in Physical Review Letters. The work results from a collaboration between POSTECH in South Korea and the Quantum Science and Technology Hub at the University of Portsmouth.
The breakthrough opens novel applications of two-photon correlation in classical light, pushing the boundaries of LIDAR. The new Coherent Two-Photon LIDAR technique overcomes range limitations associated with coherence time and demonstrates resilience in the face of external disturbances. The research could be used for such applications as autonomous vehicles, robotics, and environmental monitoring.
Researchers introduced two-photon LIDAR that eliminates range limitations imposed by coherence time to achieve accurate and precise ranging of a remote object, far beyond the coherence time dictated by the spectral bandwidth of the light source.
Unlike traditional coherent LIDAR, where the coherence time is a limiting factor, second-order interference fringes in Coherent Two-Photon LIDAR remain unaffected by the short coherence time of the light source, determined by spectral bandwidth. It takes advantage of a simple thermal light source, such as sunlight, interacting with a double slit mask with two slits separated beyond the coherent length of the source and two cameras.
The light emitted by the two slits either takes a path of known optical length toward the first detector or propagates towards a remote object at an unknown distance and, after being reflected by it, is detected by the second detector. Even in the presence of turbulence, it is possible to estimate the length of the remote object by measuring the spatial correlations in the intensities of the light detected by the two detectors.
The study reveals that Coherent Two-Photon LIDAR is robust to turbulence and ambient noise, marking a significant leap forward in the applicability of LIDAR technology within challenging environments.
