Open AccessDevelopment of a non-uniform discrete Fourier transform based high speed spectral domain optical coherence tomography system
Author(s) -
Kai Wang,
Zhihua Ding,
Tong Wu,
Chuan Wang,
Jie Meng,
MingHui Chen,
Lu Xu
Publication year - 2009
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.17.012121
Subject(s) - optics , spectrometer , optical coherence tomography , zemax , coherence (philosophical gambling strategy) , fourier transform , spectral resolution , imaging spectrometer , sensitivity (control systems) , spectral imaging , physics , materials science , computer science , spectral line , software , quantum mechanics , astronomy , electronic engineering , programming language , engineering
We develop a high speed spectral domain optical coherence tomography (SD-OCT) system based on a custom-built spectrometer and non-uniform discrete Fourier transform (NDFT) to realize minimized depth dependent sensitivity fall-off. After precise spectral calibration of the spectrometer, NDFT of the acquired spectral data is adopted for image reconstruction. The spectrometer is able to measure a wavelength range of about 138 nm with a spectral resolution of 0.0674 nm at central wavelength of 835 nm, corresponding to an axial imaging range of 2.56 mm in air. Zemax simulations and sensitivity fall-off measurements under two alignment states of the spectrometer are given. Both theoretical simulations and experiments are done to study the depth dependent sensitivity of the developed system based on NDFT in contrast to those based on conventional discrete Fourier transform (DFT) with and without interpolation. In vivo imaging on human finger from volunteer is conducted at A-scan rate of 29 kHz and reconstruction is done based on different methods. The comparing results confirm that reconstruction method based on NDFT indeed improves sensitivity especially at large depth while maintaining the coherence-function-limited depth resolution.