Fast Optical Phased Array Calibration Technique for Random Phase Modulation LiDAR

Abstract

Optical phased array (OPA) imaging technique, which uses electro-optic modulation to achieve beam steering rather than mechanical scanning, is a raster scanning imaging method with great potential due to its noninertia and high speed. However, fabrication imperfection of an OPA causes pre-designed phase modulations not yielding desired steering angles, and a time-consuming calibration is usually required before practical use. Alternatively, it is possible to obtain images with a random phase modulation OPA. In this paper, we propose a fast calibration for the random phase modulation OPA LiDAR. Experimental results demonstrate that, to obtain images of the same quality, the proposed calibration is three times faster than the calibration used in raster scanning scheme. In the meantime, the proposed calibration simultaneously retrieves the point spread function of the imaging system during the process, which can be used to remove the image blurring caused by the sidelobes and further improve the image quality.

Improving the performance of computational ghost imaging by using a quadrant detector and digital micro-scanning

“…In this case the scene consists of a binary transmissive object O . The patterns may be either randomly generated and therefore partially correlated 3 , 22 , 28 or form an orthonormal basis 8 , 9 , the latter is convenient to efficiently fully sample the scene 11 – 15 , 19 – 21 , 23 , 24 . One such orthonormal basis is derived from the Hadamard matrix, a square matrix with elements ±1 whose rows (or columns) are orthogonal to one another 29 , 30 .…”

“…Schemes such as differential detection 16 – 18 and balanced detection 19 have been developed to suppress system noise, and micro-scanning techniques 15 , 20 have been explored to further enhance SNR. Attempts to increase the frame-rate of computational ghost imaging systems have generally focused on two strategies: (i) shortening the signal acquisition time by using fast spatial light modulators, such as digital micro-mirror devices (DMD) 8 , LED arrays 21 or optical phase array 22 or (ii) reducing the total number of correlation measurements required to reconstruct an image by utilizing orthogonal sampling strategies 23 , 24 or compressive sensing 6 , 25 , i.e. under-sampling a scene and using prior knowledge of the scene such as sparsity constraints to guide the image reconstruction.…”

Single-Pixel Imaging and Its Application in Three-Dimensional Reconstruction: A Brief Review

“…There are a variety of SLM technologies used in single-pixel imaging, such as a rotating ground glass [10,11], a customized diffuser with pre-designed masks [39,72], a liquid-crystal device (LCD) [2,4], a digital micromirror device (DMD) [27,28], a light-emitting diode (LED) array [48,73], and an optical phased array (OPA) [74,75].…”

Single-Pixel MEMS Imaging Systems

“…There are other types of SLMs that can be used to establish a single-pixel imaging system, and one can select the proper modulators in different regions of interest. A summarized table (Table 1) is thus given to compare these modulators, such as DMD [86,87], LCD or LCOS [88,89], mechanical mask [90,91], customized diffuser [92,93], light-emitting diode (LED) arrays [94,95] and optical phase arrays (OPA) [96,97]. From the given table, it can be seen that the LCOS and DMD potentially satisfy the continuously increasing trend of miniature imaging systems due to their compactness.…”