Fast dispersion encoded full range optical coherence tomography for retinal imaging at 800 nm and 1060 nm.
The dispersion mismatch between sample and reference arm in frequency-domain optical coherence tomography (OCT) can be used to iteratively suppress complex conjugate artifacts and thereby increase the imaging range. In this paper, we propose a fast dispersion encoded full range (DEFR) algorithm that detects multiple signal components per iteration. The influence of different dispersion levels on the reconstruction quality is analyzed experimentally using a multilayered scattering phantom and in vivo retinal tomograms at 800 nm. Best results have been achieved with 30 mm SF11, with neglectable resolution decrease due to finite resolution of the spectrometer. Our fast DEFR algorithm achieves an average suppression ratio of 55 dB and typically converges within 5 to 10 iterations. The processing time on non-dedicated hardware was 5 to 10 seconds for tomograms with 512 depth scans and 4096 sampling points per depth scan. Application of DEFR to the more challenging 1060 nm wavelength region is also demonstrated by introducing an additional optical fibre in the sample arm.
Hofer
Bernd
B
Center of Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
Povazay
Boris
B
Unterhuber
Angelika
A
Wang
Ling
L
Hermann
Boris
B
Rey
Sara
S
Matz
Gerald
G
Drexler
Wolfgang
W
D000465:Algorithms; D016477:Artifacts; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008027:Light; D019047:Phantoms, Imaging; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence / Q000379:methods*