Measurement of the distance between two parallel precision apertures using time-of-flight method for cryogenic radiometry

Optics Express
Haiyong GanYandong Lin

Abstract

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.

Related Concepts

Related Feeds

Cell Imaging in CNS

Here is the latest research on cell imaging and imaging modalities, including light-sheet microscopy, in the central nervous system.