Single-Photon Reflectivity and Depth Imaging by Continuous Measurement of Arrival Time of Photons

Abstract

We demonstrate a reflectivity and depth imaging Lidar system based on a novel photon arrival time measurement method. In this method, the arrival time of photons in a scanning position is continuously measured with a common starting point. The number of laser pulses is counted by a specially designed field programmable gate array (FPGA) control module as the coarse time of arrival photon. Time interval between arrival photon and the nearest coming laser pulse is measured by a time-correlated single-photon counting (TCSPC) module as the fine time of arrival photon. Using the system, not only the singlephoton counting imaging can be realized, but also the first photon imaging, the first two photons imaging, etc. can be realized. A photon statistical model based on the doubly stochastic Poisson point processes, a time-gated filtering algorithm, and the reflectivity algorithm based on maximum likelihood estimation are derived. High-sensitivity reflectivity and depth imaging with a resolution of 512 × 512 pixels are achieved. The experimental results show that the horizontal spatial resolution is 2 mm, the vertical depth resolution is 5.375 cm, and the average number of photons per pixel is less than 1.3 photons.

Dual Gm-APD Polarization Lidar to Acquire the Depth Image of Shallow Semitransparent Media With a Wide Laser Pulse

“…Eqs. 7and (8) show the intensities detected by the dual Gm-APDs based on polarization transmission theory. Each measurement only depends on one of the two "attenuation factors", G1 and G2, and thus each of them can be retrieved uniquely and the paths can be separated.…”

“…where 8 2.996 10 c  m/s. Gm-APD2 detects the distance of rear surface of the shallow semitransparent media by using  …”

Wavefront detection method for orbital angular momentum modes based on conformal mapping–spatial phase-shifting interferometry

“…Besides the interest in fundamental science and research, vortex beams [26][27][28] have a number of applications. For example, in near-field optical communication, each OAM mode carrying an independent data stream can be multiplexed and demultiplexed efficiently, providing a higher transmission capacity and spectral efficiency [29].…”

Sub-Pixel Scanning High-Resolution Panoramic 3D Imaging Based on a SPAD Array

“…Using the time-correlated single-photon counting (TCSPC) technique, high temporal resolution of picosecond can be achieved. Therefore, the TCSPC lidar has great application prospect in the fields of remote sensing [1,2], spacecraft landing [3,4] and environmental monitoring [5,6], as well as low-light level imaging [7][8][9]. Particularly, with the development of single-photon avalanche diode (SPAD) array devices with independent timing capabilities for each pixel, the array-based TCSPC lidar has become a research hotspot in recent years [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”