Flash lidar based on multiple-slit streak tube imaging lidar

Experimental research on multiple-slit streak tube imaging lidar

“…System basic principle is: a laser beam illuminates to targets, and targets reflected light is focused on the front-end of remapping fiber optics by receive lens, remapping fiber optics is an image converter which will transform target image to a number of stripe images, and these stripe images are cone-coupled to photocathode of streak tube through an optical taper, streak tube will detect time and intensity information of incident light, then intensity and range(time) information of target are extracted by data processing system, and finally 48×48-pixel intensity and range images are yielded.. The principles of some key units of the system such as streak tube, remapping fiber optics are shown in Fig.1 and Streak tube is a photoelectric detector usually used in ultrafast measurement, and its temporal resolution is up to 100 attoseconds [8] until now, however in MS-STIL such precise temporal resolution is not necessary, as streak tube temporal resolution is relative to lidar range resolution [4][5] , usually 100 picoseconds resolution (0.015m) is enough for target structure detection. Remapping fiber optics is used to sample the area image on the input end and remap it to stripe images on the output end, its structure and image transformation effects are shown in Fig.…”

“…D. Gleckler [3] presented some possible applications of MS-STIL in 2000. Asher Gelbart presented a flash imaging lidar based on multiple-slit streak tube and experiment results of imaging to a target 10 meters away in laboratory of Arête associate [4], USA, 2002; and airborne experiment of imaging to a vehicle under tree 100 meters far away and mine-like targets in ocean were carried out. Harbin Institute of Technology(HIT) had constructed a MS-STIL system since 2008 [5][6] , outfield test shows that it can get images of targets 700 meters away, and images basically indicated the range, spatial and intensity information of target.…”

Experiments on the range resolution measurement of a slit Streak Tube Imaging Lidar

“…The range information can supply 3D imaging of targets. Through the intensity information, we are able to recognize the target surface material from the data supplied [3,4].…”

Femto-photography

“…Avalanche photodetector (APD) arrays can reach temporal resolutions of several tens of picoseconds if they are used in a photon starved regime where only a single photon hits a detector within a time window of tens of nanoseconds [Charbon 2007]. Repetitive illumination techniques used in incoherent LiDAR [Tou 1995;Gelbart et al 2002] use cameras with typical exposure times on the order of hundreds of picoseconds [Busck and Heiselberg 2004;Colaço et al 2012], two orders of magnitude slower than our system. Liquid nonlinear shutters actuated with powerful laser pulses have been used to capture single analog frames imaging light pulses at picosecond time resolution [Duguay and Mattick 1971].…”

“…Other sensors that use a coherent phase relation between the illumination and the detected light, such as optical coherence tomography (OCT) [Huang et al 1991], coherent LiDAR [Xia and Zhang 2009], light-in-flight holography [Abramson 1978], or white light interferometry [Wyant 2002], achieve femtosecond resolutions; however, they require light to maintain coherence (i.e., wave interference effects) during light transport, and are therefore unsuitable for indirect illumination, in which diffuse reflections remove coherence from the light. Simple streak sensors capture incoherent light at picosecond to nanosecond speeds, but are limited to a line or low resolution (20 × 20) square field of view [Campillo and Shapiro 1987;Itatani et al 2002;Shiraga et al 1995;Gelbart et al 2002;Kodama et al 1999;Qu et al 2006]. They have also been used as line scanning devices for image transmission through highly scattering turbid media, by recording the ballistic photons, which travel a straight path through the scatterer and thus arrive first on the sensor [Hebden 1993].…”