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Amplified, frequency
swept lasers for OCT imaging: design and scaling principles
by R. Huber, M. Wojtkowski, K. Taira, J. G. Fujimoto,
K. Hsu; Optics Express, v.13, no.9,
p.3513, May 2 (2005).
Abstract: We demonstrate
a high-speed, frequency swept, 1300 nm laser source
for frequency domain reflectometry and OCT with Fourier
domain/swept-source detection. The laser uses a fiber
coupled, semiconductor amplifier and a tunable fiber
Fabry-Perot filter. We present scaling principles
which predict the maximum frequency sweep speed and
trade offs in output power, noise and instantaneous
linewidth performance. The use of an amplification
stage for increasing output power and for spectral
shaping is discussed in detail. The laser generates
~45 mW instantaneous peak power at 20 kHz sweep rates
with a tuning range of ~120 nm full width. In frequency
domain reflectometry and OCT applications the frequency
swept laser achieves 108 dB sensitivity and ~10 m
axial resolution in tissue. We also present a fast
algorithm for real time calibration of the fringe
signal to equally spaced sampling in frequency for
high speed OCT image preview.
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Express
© 2005 Optical
Society of America
Swept source optical
coherence tomography using an all-fiber 1300nm fiber
ring swept laser source by M.A. Choma, K. Hsu,
J.A. Izatt ; J. Biomedical Optics
(2005).
Abstract: The
increased sensitivity of spectral domain optical coherence
tomography (OCT) has driven the development of a new
generation of technologies in OCT, including rapidly
tunable, broad bandwidth swept laser sources and spectral
domain OCT interferometer topologies. In this work,
the operation of a turnkey 1300-NM swept laser source
is demonstrated. This source has a fiber ring cavity
with a semiconductor optical amplifier gain medium.
Intracavity mode selection is achieved with an in-fiber
tunable fiber Fabry-Perot filter. A novel optoelectronic
technique that allows for even sampling of the swept
source OCT signal in k space also is described. A
differential swept source OCT system is presented,
and images of in vivo human cornea and skin are presented.
Lastly, the effects of analog-to-digital converter
aliasing on image quality in swept source OCT are
discussed.
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article...
©
2005 Used with permission of the authors
High speed frequency
swept light source for Fourier domain OCT at 20KHz A-scan
rate by R. Huber, K. Hsu, K. Taira, M. Wojtkowski,
T.H. Ko, and J.G. Fujimoto; SPIE Photonics
West, Biomedical Optics, Session 5690-18 (2005).
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article...
©
2005 Used with permission of the authors
Heterodyne swept-source
optical coherence tomography for complete complex conjugate
ambiguity removal by A. Maheshwari, M.A. Choma, J.A. Izatt;
SPIE Photonics West, Biomedical Optics, Session 5690-17 (2005).
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article...
©
2005 Used with permission of the authors
Swept-wavelength
source for optical coherence tomography in the 1 µm
range by F.D. Nielsen, L. Thrane, J. Black, K.
Hsu, A. Bjarklev, P. E. Andersen; European
Conference on Biomedical Optics (2005).
Abstract: Two swept wavelength
light sources based on Ytterbium doped fibre amplifiers
are demonstrated. The filtered output from a superfluorescent
source is scanned over 20 NM, and used for tomography
with an axial resolution of <40 µm. Dynamic
properties of a swept wavelength YDFA based ring laser
is investigated. This is the first reported results
with dynamically swept sources centered in the 1 µm
wavelength range, which is expected to be important
for future development of optical coherence tomography
systems for retinal imaging.
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article...
Instantaneous complex
conjugate resolved spectral domain and swept-source
OCT using 3x3 fiber couplers by M.V. Sarunic,
M.A. Choma, C. Yang, J.A. Izatt; Optics Express, v.13, no.3, p.957, February 7 (2005).
Abstract: We report that
the complex conjugate artifact in Fourier domain optical
coherence tomography approaches (including spectral
domain and swept source OCT) may be resolved by the
use of novel interferometer designs based on 3x3 and
higher order fiber couplers. Interferometers built
from NxN (N>2) truly fused fiber couplers provide
simultaneous access to non-complementary phase components
of the complex interferometric signal. These phase
components may be converted to quadrature components
by trigonometric manipulation, then inverse Fourier
transformed to obtain A-scans and images with resolved
complex conjugate artifact. We demonstrate instantaneous
complex conjugate resolved Fourier domain OCT using
3x3 couplers in both spectral domain and swept source
implementations. Complex conjugate artifact suppression
by factors of ~20dB and ~25dB are demonstrated for
spectral domain and swept source implementations,
respectively.
Read full article at Optics
Express
© 2005 Optical
Society of America
Removal of a mirror
image and enhancement of the signal-to-noise ratio
in Fourier-domain optical coherence tomography using
an electro-optic phase modulator by J. Zhang,
J.S. Nelson, and Z. Chen; Optics Letters,
v. 30, no. 2, January 15, p.147-149 (2005).
Abstract: A novel swept-laser-based
Fourier-domain optical coherence tomography system
using an electro-optic phase modulator was demonstrated.
The imaging range was doubled by cancellation of the
mirror image. The elimination of low-frequency noises
resulting from dc and autocorrelation terms increased
the sensitivity by 20dB.
Read full article at Optics
Letters
© 2005 Optical
Society of America
Full range polarization-sensitive
Fourier domain optical coherence tomography by
J. Zhang, W. Jung, J.S. Nelson, Z. Chen; Optics
Express, v.12, no.24, p.6033, November 29 (2004)
Abstract: A swept source
based polarization- sensitive Fourier domain optical
coherence tomography (FDOCT) system was developed
that can acquire the Stokes vectors, polarization
diversity intensity and birefringence images in biological
tissue by reconstruction of both the amplitude and
phase terms of the interference signal. The Stokes
vectors of the reflected and backscattered light from
the sample were determined by processing the analytical
complex fringe signals from two perpendicular polarization
detection channels. Conventional time domain OCT (TDOCT)
and spectrometer based FDOCT systems are limited by
the fact that the input polarization states are wavelength
dependent. The swept source based FDOCT system overcomes
this limitation and allows accurate setting of the
input polarization states. From the Stokes vectors
for two different input polarization states, the polarization
diversity intensity and birefringence images were
obtained.
Read full article at Optics
Express
© 2004 Optical
Society of America
Sensitivity advantage
of swept source and Fourier domain optical coherence
tomography by M. A. Choma, M. V. Sarunic, C. Yang,
J. A. Izatt Express, v.11, no.18,
p.2183, September 8 (2003).
Abstract: We present theoretical and experimental
results which demonstrate the superior sensitivity of swept source (SS) and Fourier
domain (FD) optical coherence tomography (OCT) techniques over the conventional time
domain (TD) approach. We show that SS- and FD-OCT have equivalent expressions for system
signal-to-noise ratio which result in a typical sensitivity advantage of 20-30dB over TD-OCT.
Experimental verification is provided using two novel spectral discrimination (SD) OCT
systems: a differential fiber-based 800nm FD-OCT system which employs deep-well photodiode
arrays, and a differential 1300nm SS-OCT system based on a swept laser with an 87nm tuning
range.
Read full article at Optics
Express
©
2003 Optical Society of America
Polarization based Microscopy using a Fiber Optic Spectral Polarimeter
by E. Kim, D.P. Dave, T.E. Milner;
SPIE Proceeding, 4617, p.191 (2002).
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article...
©
2002 Used with permission of the authors
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