Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Polarization sensitive optical frequency domain imaging system for endobronchial imaging

Open Access Open Access

Abstract

A polarization sensitive endoscopic optical frequency domain imaging (PS-OFDI) system with a motorized distal scanning catheter is demonstrated. It employs a passive polarization delay unit to multiplex two orthogonal probing polarization states in depth, and a polarization diverse detection unit to detect interference signal in two orthogonal polarization channels. Per depth location four electro-magnetic field components are measured that can be represented in a complex 2x2 field matrix. A Jones matrix of the sample is derived and the sample birefringence is extracted by eigenvalue decomposition. The condition of balanced detection and the polarization mode dispersion are quantified. A complex field averaging method based on the alignment of randomly pointing field phasors is developed to reduce speckle noise. The variation of the polarization states incident on the tissue due to the circular scanning and catheter sheath birefringence is investigated. With this system we demonstrated imaging of ex vivo chicken muscle, in vivo pig lung and ex vivo human lung specimens.

© 2015 Optical Society of America

Full Article  |  PDF Article
More Like This
High-speed polarization sensitive optical frequency domain imaging with frequency multiplexing

W.Y. Oh, S.H. Yun, B.J. Vakoc, M. Shishkov, A.E. Desjardins, B.H. Park, J.F. de Boer, G.J. Tearney, and B.E. Bouma
Opt. Express 16(2) 1096-1103 (2008)

Polarization-sensitive optical frequency domain imaging based on unpolarized light

Ki Hean Kim, B. Hyle Park, Yupeng Tu, Tayyaba Hasan, Byunghak Lee, Jianan Li, and Johannes F. de Boer
Opt. Express 19(2) 552-561 (2011)

High speed miniature motorized endoscopic probe for optical frequency domain imaging

Jianan Li, Mattijs de Groot, Frank Helderman, Jianhua Mo, Johannes M. A. Daniels, Katrien Grünberg, Tom G. Sutedja, and Johannes F. de Boer
Opt. Express 20(22) 24132-24138 (2012)

Supplementary Material (2)

Media 1: MOV (2715 KB)     
Media 2: MOV (5709 KB)     

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1 Endoscopic PS-OFDI System schematic. FC: fiber-optic coupler, PC: polarization controller, FBG: fiber Bragg grating.
Fig. 2
Fig. 2 Balanced spectra of reference arm input. Horizontal axis: wavelength. Vertical axis: Balanced power at the receiver. Green trace: spectrum acquired by the horizontal (H) channel; Magenta trace: spectrum acquired by the vertical (V) channel.
Fig. 3
Fig. 3 Stokes vector representation of the evolution of a reflected state from the sample arm as a function of wavelength, rendered through open access MatLab code [39]. Blue trace: state 1; Red trace: state 2.
Fig. 4
Fig. 4 Diagram of field phasor alignment. For each sampling point there is a field matrix E consisting of four field phasors. (a) The neighboring points have similar relative phase angles between these phasors, though global phase adds random rotation on all of them. (b) By aligning the vector sum of the four phasors to the positive real axis, the neighboring phasors are aligned correspondingly. The colored arrows represent field phasors. The dash arrow represents the vector sum of the four phasors.
Fig. 5
Fig. 5 Absolute phases of H 1 + H 2 + V 1 + V 2 components of a B-scan measurement, before (a) and after (b) phasor alignment. The grayscale ranges from -π to + π It is clearly seen that before the alignment the phases are totally random while after the alignment the phases have only slow variation due to tissue birefringence.
Fig. 6
Fig. 6 Measured Stokes parameters and trace of Stokes vectors for a whole B-scan (960 A-lines) for Fresnel reflection signals on the inner (top row) and outer (bottom row) surface of the sheath. Blue trace: state 1; Red trace: state 2.
Fig. 7
Fig. 7 Schematic diagram of the optics of the catheter. For simplicity, accessorial holders and motor wires are not shown. Polarization state changes occur predominantly at A: reflection on metallic mirror; and B: propagation in Pebax sheath.
Fig. 8
Fig. 8 Images of ex vivo chicken muscle and tendon. Top: structural image; Bottom-left: phase retardation image without field averaging; Bottom-right: phase retardation image with field averaging. For the phase retardation images the grayscale ranges from -π to + π. Position between 5 o’clock and 6 o’clock is blocked by the motor wires.
Fig. 9
Fig. 9 Image of in vivo pig bronchus. Left: structural image; Right: phase retardation image. Position between 9 o’clock and 10 o’clock is blocked by the motor wires. EP: epithelium, LP: lamina propria, SM: submucosa, CA: cartilage. IS/OS: Inner/Outer surface of catheter sheath. Videos are available online (Media 1 and Media 2).
Fig. 10
Fig. 10 Image of ex vivo human bronchus. Left: structural image; Right: phase retardation image. Position between 5 o’clock and 6 o’clock is blocked by the motor wires.

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

r= I var I total , I var = ( I(λ) I(λ) ) 2 .
Δϕ=ΔτΔω.
Δω= 2πcΔλ / λ 0 2 .
Δτ= Δϕ / Δω = Δϕ λ 0 2 / 2πcΔλ .
Θ=arctan( Im( H 1 + H 2 + V 1 + V 2 ) Re( H 1 + H 2 + V 1 + V 2 ) ).
Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved