Acousto-optic tunable filter for dispersion characterization of time-domain optical coherence tomography systems
Authors: Catherine Chin, Florin Toadere, Thomas Feuchter, Lasse Leick, Peter Moselund, Adrian Bradu, and Adrian Podoleanu
Journal: Applied Optics Vol. 55, Issue 21, pp. 5707-5714 (2016) Link to article
Published: July 20th, 2016
Also featured on OCTnews.org
Archieved on Kent Academic Repository (KAR)
A broadband supercontinuum light source with an acousto-optic tunable filter (AOTF) are used to characterize dispersion in two time-domain OCT systems, at 850 and 1300 nm. The filter is designed to sweep across two spectral ranges, which are restricted here from 800 to 900 nm and from 1200 to 1500 nm, respectively. Dispersion compensation for 850 nm was achieved with a spectral delay line. Dispersion compensation for 1300 nm was achieved using BK 7 rod glasses in the reference arm. The AOTF allows evaluation of dispersion in under as well as overcompensated systems. The AOTF method is based on wavelength dependence of the optical path difference corresponding to the maximum strength of the interference signal recorded using a mirror as object. Comparison is made between the AOTF method and the more usual method based on measurement of the full width at half-maximum of the autocorrelation peak. This comparison shows that the AOTF method is more accurate in terms of evaluation of the dispersion left uncompensated after each adjustment. The AOTF method additionally provides information on the direction of dispersion compensation.
For full article, go to OSA Publishing website.
Featured autocorrelation function curves for different values of BK7 rod glasses. For more details on methodology used, and comparison between AOTF and FWHM of autocorrelation peak, please read the full article from OSA Publishing site.
Optical systems used in this study:
- Supercontinuum laser: NKT Photonics SuperK Extreme EXR20
- Acousto optic tunable filter: NKT Photonics SuperK Select
- Broadband spectral splitter: NKT Photonics SuperK Split
For more information on this paper, please contact the author Catherine at cc539 ‘at’ kent.ac.uk