{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T15:52:38Z","timestamp":1780674758572,"version":"3.54.1"},"reference-count":27,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2020,12,14]],"date-time":"2020-12-14T00:00:00Z","timestamp":1607904000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In a free space optical communication system, the beacon light will lose most of its energy after long-distance transmission, and the background light from the universe will strongly interfere with it. The four-quadrant detector (4QD) has been widely used in optical communication systems as a high-precision spot position detection sensor. However, if the light signal falling on the 4QD is too weak, the electrical signal of the output position will be very weak, and it will easily be affected by or even submerged in noise. To solve this problem, we propose a method for improving the spot position detection accuracy. First, we analyzed the solution relationship between the actual position of the spot and the output signal of the 4QD, with a Gaussian spot as the incident light model. The output current signal of the detector was then transimpedance-amplified by an analog circuit and the output voltage signal with noise was digitally filtered. An error compensation factor and the gap size of the detector were introduced into the traditional spot position detection model. High-precision spot position information for the 4QD in a complex environment was then obtained using the improved spot position detection model. Experimental results show that the maximum spot position detection error for this method was only 0.0277 mm, and the root mean square error was 0.0065 mm, when the 4QD was in a high background noise environment. The spot position detection accuracy was significantly improved compared with traditional detection algorithms. Real-time detection can therefore be achieved in practical applications.<\/jats:p>","DOI":"10.3390\/s20247164","type":"journal-article","created":{"date-parts":[[2020,12,14]],"date-time":"2020-12-14T21:25:08Z","timestamp":1607981108000},"page":"7164","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["A Method for Improving the Detection Accuracy of the Spot Position of the Four-Quadrant Detector in a Free Space Optical Communication System"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8445-1391","authenticated-orcid":false,"given":"Xuan","family":"Wang","sequence":"first","affiliation":[{"name":"Xi\u2019an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi\u2019an 710119, China"},{"name":"School of Electronic and Information Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiuqin","family":"Su","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi\u2019an 710119, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guizhong","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Electronic and Information Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junfeng","family":"Han","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi\u2019an 710119, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaidi","family":"Wang","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi\u2019an 710119, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenhua","family":"Zhu","sequence":"additional","affiliation":[{"name":"Xi\u2019an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi\u2019an 710119, China"},{"name":"University of Chinese Academy of Sciences, Beijing 100049, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"126033","DOI":"10.1016\/j.optcom.2020.126033","article-title":"On the performance of optical wireless communication links impaired by time jitter, M-turbulence and pointing errors","volume":"472","author":"Roumelas","year":"2020","journal-title":"Opt. Commun."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1038\/nphoton.2016.65","article-title":"Advances in terahertz communications accelerated by photonics","volume":"10","author":"Nagatsuma","year":"2016","journal-title":"Nat. Photon"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.optcom.2016.11.032","article-title":"Real-time optical OFDM transmissions with spectral efficiency up to 6.93 bit\/s\/Hz over 50 km SSMF IMDD systems","volume":"387","author":"Zhang","year":"2017","journal-title":"Opt. Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1049\/iet-opt.2017.0073","article-title":"Experimental demonstration of high spectral efficiency SC-FDMA with soft clipping for optical wireless communication systems","volume":"12","author":"Puntsri","year":"2018","journal-title":"IET Optoelectron."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1109\/TCST.2018.2884197","article-title":"Intelligent Proportional\u2013Integral\u2013Derivative Control-Based Modulating Functions for Laser Beam Pointing and Stabilization","volume":"28","author":"Asiri","year":"2020","journal-title":"IEEE Trans. Control. Syst. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1109\/TMECH.2015.2427379","article-title":"Receding-Horizon Adaptive Control of Laser Beam Jitter","volume":"21","author":"Tsuchiya","year":"2015","journal-title":"IEEE\/ASME Trans. Mechatronics"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7873","DOI":"10.1109\/TIE.2018.2885731","article-title":"Adaptive Control of a Piezo-Actuated Steering Mirror to Restrain Laser-Beam Jitter","volume":"66","author":"Zhu","year":"2019","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"041001","DOI":"10.1115\/1.4003372","article-title":"Laser Beam Jitter Control Using Recursive-Least-Squares Adaptive Filters","volume":"133","author":"Yoon","year":"2011","journal-title":"J. Dyn. Syst. Meas. Control."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Zhang, W., Guo, W., Zhang, C., and Zhang, S. (2019). An Improved Method for Spot Position Detection of a Laser Tracking and Positioning System Based on a Four-Quadrant Detector. Sensors, 19.","DOI":"10.3390\/s19214722"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"075","DOI":"10.1088\/1674-4527\/17\/7\/75","article-title":"Optical fiber positioning based on four-quadrant detector with Gaussian fitting method","volume":"17","author":"Liu","year":"2017","journal-title":"Res. Astron. Astrophys."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Gao, S., Liu, H., Zhang, H., Zhang, X., and Chen, J. (2019). Improve the Detection Range of Semi-Active Laser Guidance System by Temperature Compensation of Four-Quadrant PIN Detector. Sensors, 19.","DOI":"10.3390\/s19102284"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"072903","DOI":"10.7498\/aps.61.072903","article-title":"Error analysis of four-quadrant-based tracking sensor when dead zone is inevitable","volume":"61","author":"Ma","year":"2012","journal-title":"Acta Phys. Sin."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Yu, J., Li, Q., Li, H., Wang, Q., Zhou, G., He, D., Xu, S., Xia, Y., and Huang, Y. (2019). High-Precision Light Spot Position Detection in Low SNR Condition Based on Quadrant Detector. Appl. Sci., 9.","DOI":"10.3390\/app9071299"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/S0168-9002(01)00843-9","article-title":"Simulation of a low atmospheric-noise modified four-quadrant position sensitive detector","volume":"466","author":"Bertilsson","year":"2001","journal-title":"Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1109\/19.481361","article-title":"Positioning resolution of the position-sensitive detectors in high background illumination","volume":"45","author":"Makynen","year":"1996","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Meng, X., Qian, W., Cai, G., and Gao, Q. (2018, January 20). Research on correction algorithm of laser positioning system based on four quadrant detector. Proceedings of the Fourth Seminar on Novel Optoelectronic Detection Technology and Application, Nanjing, China.","DOI":"10.1117\/12.2307139"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6806","DOI":"10.1016\/j.ijleo.2013.06.010","article-title":"Investigation of positioning algorithm and method for increasing the linear measurement range for four-quadrant detector","volume":"124","author":"Chen","year":"2013","journal-title":"Optik"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"081102","DOI":"10.1063\/1.3326078","article-title":"Improved measurement accuracy of the quadrant detector through improvement of linearity index","volume":"96","author":"Cui","year":"2010","journal-title":"Appl. Phys. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1692","DOI":"10.1364\/OL.36.001692","article-title":"Analysis and improvement of Laguerre-Gaussian beam position estimation using quadrant detectors","volume":"36","author":"Cui","year":"2011","journal-title":"Opt. Lett."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"8049","DOI":"10.1364\/AO.54.008049","article-title":"Improved measurement accuracy of spot position on an InGaAs quadrant detector","volume":"54","author":"Wu","year":"2015","journal-title":"Appl. Opt."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Li, Q., Xu, S., Yu, J., Yan, L., and Huang, Y. (2019). An Improved Method for the Position Detection of a Quadrant Detector for Free Space Optical Communication. Sensors, 19.","DOI":"10.3390\/s19010175"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"164226","DOI":"10.1016\/j.ijleo.2020.164226","article-title":"A calibration and correction method for the measurement system based on four-quadrant detector","volume":"204","author":"Zhang","year":"2020","journal-title":"Optik"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"34529","DOI":"10.1364\/OE.26.034529","article-title":"Optimal ellipsometric parameter measurement strategies based on four intensity measurements in presence of additive Gaussian and Poisson noise","volume":"26","author":"Li","year":"2018","journal-title":"Opt. Express"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6898","DOI":"10.1364\/AO.57.006898","article-title":"Quadrant response model and error analysis of four-quadrant detectors related to the non-uniform spot and blind area","volume":"57","author":"Zhang","year":"2018","journal-title":"Appl. Opt."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"012122","DOI":"10.1088\/1742-6596\/1633\/1\/012122","article-title":"High-precision spot positioning algorithm based on four-quadrant detector","volume":"1633","author":"Xiao","year":"2020","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Ge, B., Zhang, H., Jiang, L., Li, Z., and Butt, M.M. (2019). Adaptive Unscented Kalman Filter for Target Tracking with Unknown Time-Varying Noise Covariance. Sensors, 19.","DOI":"10.3390\/s19061371"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"163941","DOI":"10.1016\/j.ijleo.2019.163941","article-title":"Investigation of high-precision algorithm for the spot position detection for four-quadrant detector","volume":"203","author":"Xuan","year":"2020","journal-title":"Optik"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/24\/7164\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:44:51Z","timestamp":1760179491000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/24\/7164"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,14]]},"references-count":27,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["s20247164"],"URL":"https:\/\/doi.org\/10.3390\/s20247164","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,14]]}}}