Rapid nanometer-precision autocorrelator

Imogen Morland, Feng Zhu, Paul Dalgarno, Jonathan Leach*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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The precise measurement of a target depth has applications in biophysics and nanophysics, and non-linear optical methods are sensitive to intensity changes on very small length scales. By exploiting the high sensitivity of an autocorrelator’s dependency on path length, we propose a technique that achieves ≈30 nm depth precision for each pixel in 30 seconds. Our method images up-converted pulses from a non-linear crystal using a sCMOS (scientific Complementary Metal–Oxide–Semiconductor) camera and converts the intensity recorded by each pixel to a delay. By utilising statistical estimation theory and using the data from a set of 32×32 pixels, the standard error (SE) of the detected delay falls below 1 nm after 30 seconds of measurement. Numerical simulations show that this result is extremely close to what can be achieved with a shot-noise-limited source and is consistent with the precision that can be achieved with a sCMOS camera.

Original languageEnglish
Pages (from-to)46020-46030
Number of pages11
JournalOptics Express
Issue number26
Early online date5 Dec 2022
Publication statusPublished - 19 Dec 2022

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


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