Open AccessMeasurement of the distance between two parallel precision apertures using time-of-flight method for cryogenic radiometry
Author(s) -
Haitao Gan,
Wende Liu,
Nan Xu,
Jianwei Li,
Yangyang Wang,
Mingyu Zhang,
Yingwei He,
Xiangliang Liu,
Yangting Fu,
Yandong Lin
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.389569
Subject(s) - optics , radiometry , radiance , oscilloscope , metrology , laser , femtosecond , radiometer , physics , measure (data warehouse) , detector , database , computer science
Time-of-flight method was adopted to measure the distance between two parallel precision apertures utilized in a vacuum chamber for cryogenic radiometry. The diameters of the apertures are 9 mm and 8 mm, respectively. A 1550-nm femtosecond pulse laser, a 70-GHz photodetector, and a 30-GHz oscilloscope were used to measure the round-trip flight time difference between the flat front surfaces of the two precision apertures. The distance between the apertures was analyzed to be 0.36423 m with a relative standard uncertainty of 0.004%. The non-contact distance measurement method is useful for applications such as low background infrared radiance measurement system based on an absolute cryogenic radiometer.