The ability to detect motion and track a moving object hidden around a corner or behind a wall provides a crucial advantage when physically going around the obstacle is impossible or dangerous. Previous methods have demonstrated that it is possible to reconstruct the shape of an object hidden from view. However, these methods do not enable the tracking of movement in real time. We demonstrate a compact non-line-of-sight laser ranging technology that relies on the ability to send light around an obstacle using a scattering floor and then detect the return signal from a hidden object within only a few seconds of acquisition time. By detecting this signal with a single-photon avalanche diode (SPAD) camera, we follow the movement of an object located a metre away from the camera with centimetre precision. We discuss the possibility of applying this technology to a variety of real-life situations in the near future.
At a glance
- First-photon imaging. Science 343, 58–61 (2014). et al.
- 3d computational imaging with single-pixel detectors. Science 340, 844–847 (2013). et al.
- 2005). Introduction to Lidar (Springer,
- Laser depth measurement based on time-correlated single-photon counting. Opt. Lett. 22, 543–545 (1997). , , , &
- Recovering three-dimensional shape around a corner using ultrafast time-of-flight imaging. Nature Commun. 3, 745 (2012). et al.
- Single-shot compressed ultrafast photography at one hundred billion frames per second. Nature 516, 74–77 (2015). , , &
- Single-photon sensitive light-in-flight imaging. Nature Commun. 6, 6021 (2015). et al.
- Non-line-of-sight imaging using a time-gated single photon avalanche diode. Opt. Express 23, 20997 (2015). , , , &
- Radar detection of moving objects around corners. Proc. SPIE 7308, 73080V (2009). et al.
- 2010 IEEE Int. Conf. Acoust, Speech Signal Process. 3894–3897 (2010). et al. in
- Reconstruction of hidden 3d shapes using diffuse reflections. Opt. Express 20, 19096–19108 (2012). , , , &
- Advanced short-wavelength infrared range-gated imaging for ground applications in monostatic and bistatic configurations. Appl. Opt. 48, 5956–5969 (2009). et al.
- Universal optimal transmission of light through disordered materials. Phys. Rev. Lett. 101, 120601 (2008). &
- Controlling waves in space and time for imaging and focusing in complex media. Nature Photon. 6, 283–292 (2012). , , &
- Non-invasive imaging through opaque scattering layers. Nature 491, 232–234 (2012). et al.
- Looking around corners and through thin turbid layers in real time with scattered incoherent light. Nature Photon. 6, 459–553 (2012). , &
- Non-invasive single-shot imaging through scattering layers and around corners via speckle correlations. Nature Photon. 8, 784–790 (2014). , , &
- A 32×32 50ps resolution 10 bit time to digital converter array in 130nm CMOS for time correlated imaging. In Custom Integr. Circ. Conf. 2009 77–80 (IEEE, 2009). et al.
- Low dark count single-photon avalanche diode structure compatible with standard nanometer scale CMOS technology. Photon. Technol. Lett. IEEE 21, 1020–1022 (2009). , &
- Design and characterization of a CMOS 3-d image sensor based on single photon avalanche diodes. IEEE J. Solid-State Circuits 40, 1847–1854 (2005). , , &
- 1984). & Time-Correlated Single Photon Counting (Academic Press,
- 2005). Advanced Time-correlated Single Photon Counting Techniques (Springer,
- 1979). & Optimal Filtering (Prentice-Hall,
- Detecting moving objects, ghosts, and shadows in video streams. IEEE Trans. Pattern Anal. Machine Intel. 25, 1337–1342 (2003). , , &
- Proc. Int. Conf. Pattern Recog. 1, 495 (IEEE, 1998). & in
- Ranging and three-dimensional imaging using time-correlated single-photon counting and point-by-point acquisition. IEEE J. Sel. Top. Quant. Electron. 13, 1006–1015 (2007). &
- Demonstration of literal three-dimensional imaging. Appl. Opt. 38, 1833–1840 (1999). et al.
- Three-dimensional imaging laser radar with a photon-counting avalanche photodiode array and microchip laser. Appl. Opt. 41, 7671–7678 (2002). et al.