US 12,222,241 B2
Method and apparatus for extracting avalanche signal
Liuping Chen, Beijing (CN); Yongsheng Fan, Beijing (CN); Liting Tong, Beijing (CN); Xiangsheng She, Beijing (CN); Nan Li, Beijing (CN); Qibing Wang, Beijing (CN); and Xiangkui Wan, Beijing (CN)
Assigned to QUDOOR TECHNOLOGIES INC., Beijing (CN)
Appl. No. 18/684,686
Filed by QUDOOR TECHNOLOGIES INC., Beijing (CN)
PCT Filed Aug. 12, 2022, PCT No. PCT/CN2022/111963
§ 371(c)(1), (2) Date Feb. 18, 2024,
PCT Pub. No. WO2023/020370, PCT Pub. Date Feb. 23, 2023.
Claims priority of application No. 202110945841.X (CN), filed on Aug. 18, 2021.
Prior Publication US 2024/0377251 A1, Nov. 14, 2024
Int. Cl. G01J 1/44 (2006.01); H01L 31/107 (2006.01)
CPC G01J 1/44 (2013.01) [H01L 31/107 (2013.01); G01J 2001/4466 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for extracting an avalanche signal, comprising:
obtaining an avalanche photodiode (APD) signal output by a single-photon detector, wherein the APD signal comprises an upper spike and a lower spike, the upper spike is generated along with a rising edge of a gating signal, and the lower spike is generated along with a falling edge of the gating signal;
determining a delay position of the upper spike in the APD signal, so as to determine a delay position of the lower spike in the APD signal based on a pulse width of the gating signal;
shifting a coincidence gate signal, so as to align a delay position of a falling edge of the coincidence gate signal with the delay position of the lower spike in the APD signal, wherein a pulse width of the coincidence gate signal is smaller than the pulse width of the gating signal; and
extracting, as the avalanche signal, a second pulse that is generated through an AND operation on a first pulse that is generated by a partial signal, exceeding a discrimination threshold, in the APD signal and the coincidence gate signal.