Ray tracing based path-length calculations for polarized light tomographic imaging

Rakesh Manjappa; Rajan Kanhirodan

doi:10.1117/12.2189190

1 September 2015 Ray tracing based path-length calculations for polarized light tomographic imaging

Rakesh Manjappa, Rajan Kanhirodan

Proceedings Volume 9613, Polarization Science and Remote Sensing VII; 96130N (2015) https://doi.org/10.1117/12.2189190
Event: SPIE Optical Engineering + Applications, 2015, San Diego, California, United States

Abstract

A ray tracing based path length calculation is investigated for polarized light transport in a pixel space. Tomographic imaging using polarized light transport is promising for applications in optical projection tomography of small animal imaging and turbid media with low scattering. Polarized light transport through a medium can have complex effects due to interactions such as optical rotation of linearly polarized light, birefringence, di-attenuation and interior refraction. Here we investigate the effects of refraction of polarized light in a non-scattering medium. This step is used to obtain the initial absorption estimate. This estimate can be used as prior in Monte Carlo (MC) program that simulates the transport of polarized light through a scattering medium to assist in faster convergence of the final estimate. The reflectance for p-polarized (parallel) and s-polarized (perpendicular) are different and hence there is a difference in the intensities that reach the detector end. The algorithm computes the length of the ray in each pixel along the refracted path and this is used to build the weight matrix. This weight matrix with corrected ray path length and the resultant intensity reaching the detector for each ray is used in the algebraic reconstruction (ART) method. The proposed method is tested with numerical phantoms for various noise levels. The refraction errors due to regions of different refractive index are discussed, the difference in intensities with polarization is considered. The improvements in reconstruction using the correction so applied is presented. This is achieved by tracking the path of the ray as well as the intensity of the ray as it traverses through the medium.

Citation Download Citation

Rakesh Manjappa and Rajan Kanhirodan "Ray tracing based path-length calculations for polarized light tomographic imaging", Proc. SPIE 9613, Polarization Science and Remote Sensing VII, 96130N (1 September 2015); https://doi.org/10.1117/12.2189190

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
7 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Refraction

Refractive index

Polarization

Light scattering

Tomography

Reconstruction algorithms

Sensors

Show All Keywords

Keywords/Phrases

Search In:

Publication Years