Abstract:
BACKGROUND: K-trigger signals from light source or external
Mach-Zehnder interferometer are commonly used in swept source optical
coherence tomography (SS-OCT) to achieve interference signal sampling and
resolution enhancement. But extra signal transmission time is required due
to the increased complexity of interference system using k-trigger signals,
resulting in a misalignment (a.k.a., time delay) between the k-trigger and
the interference signals. OBJECTIVE: The objective of this paper is to propose a numerical
technique to correct the time delay between these two signals. METHODS: The time delay is iterated in this technique and each
iterated correction result is evaluated through calculating the full width
at half maximum (FWHM) of peaks in time-domain. The precise alignment
between the k-trigger and interference signals coincides with the minimum
value of FWHM. RESULTS: The experimental results show that the FWHM can be
improved by up to 50% using this time delay correction technique. CONCLUSIONS: The proposed technique assists to provide precise
sample tomography, thus enhancing the way of understanding sample
characteristic.
Keywords: (110.4500) Optical coherence tomography (OCT), (070.0070) fourier optics and signal processing, (070.4340) nonlinear optical signal processing, (350.5730) resolution, (080.1753) computation methods
