Overcoming the shot-noise limitation of three-dimensional active imaging

Abstract

Depth resolution is limited by the photoelectron shot noise in conventional gain-modulated active three-dimensional (3D) imaging methods. A proposed method, which is based on photon intensity correlation, is presented to overcome the depth resolution limitation. The signal photons are amplified by an imaging intensifier, and are then divided into two beams by a beam splitter. The theory shows that the shot-noise limitation is broken using the strong intensity coherence between the two beams. The experiment results show that the depth resolution of the correlated active 3D imaging method is three times better than that of the shot-noise limitation.

Vision-guided three-dimensional range-gated imaging based on epistemic uncertainty estimation

“…To improve this problem, Jin and Zhang et al proposed a gain modulation method to achieve 3D imaging from two sliced images. 3,4 They performed high-precision 3D imaging at a particular target distance. 5,6 Nevertheless, this method employs narrow laser pulses and uses a modulated gain selector gate, leading to the system's high complexity.…”

Trapping of low-refractive-index nanoparticles in a hollow dark spherical spot

“…Bottle beams that have a zero intensity region surrounded by light all around have been produced by many methods both theoretically and experimentally [22][23][24], and their applications in trapping atoms are reported [25,26]. Besides, three-dimensional bottle beams have been studied and widely used for optical tweezers [27][28][29][30], however the axial gradient force is too weak to manipulate the low-refractive-index nanoparticle along the optical axis. In the last decade, 4Pi microscopy was developed to improve the axial resolution and synthesize focal field with various impressive characteristics through modulating the polarization and phase of the illumination [31][32][33][34][35].…”

Multireturn three-dimensional active imaging based on compressive sensing

“…One of the main faults of this technique is low detection speed, which limits its application. Accordingly, the intensity correlation [5] and gain modulation [6,7] methods have been proposed. These methods use a relatively high signal-to-noise ratio (SNR) to subdivide the detection range to increase the detection speed.…”

“…In the coded methods [7,8], the values of the profile are encoded. To combine the gate-coding method with CS, the profile is written into a vector.…”

“…If the signal sparse number is k, the number of detections m should meet m ≥ k logn∕k: (6) For the time-gated viewing technique [1], the return signal number is assumed to be arbitrary and the distance resolution is assumed to be equal to the gate width; thus, the number of detections is the distance parts n. For the gain-modulated or intensity correlation method [4][5][6][7], the return signal number is assumed to be one and the distance resolution is assumed to be much less than the gate width; thus, the number of detections is two. The CS assumes that the return signal is sparse and has a distance resolution much less than the gate width; thus, the number of detection is between two and n [Eq.…”