Mueller matrix retinal imager with optimized polarization conditions

Abstract

A new Mueller matrix polarimeter was used to image the retinas of normal subjects. Light from a linearly polarized 780 nm laser was passed through a system of variable retarders and scanned across the retina. Light returned from the eye passed through a second system of retarders and a polarizing beamsplitter to two confocal detection channels. Optimization of the polarimetric data reduction matrix was via a condition number metric. The accuracy and repeatability of polarization parameter measurements were within ± 5%. The magnitudes and orientations of retardance and diattenuation, plus depolarization, were measured over 15° of retina for 15 normal eyes.

Optimization and performance criteria of a Stokes polarimeter based on two variable retarders

“…well-calibrated polarimeter) and a vector of measures I, the value of S can be obtained just by solving Eq. (2). Note that for a fully description of the solution S, a minimum number of four independent polarization analyzers are required.…”

“…Polarimetric techniques are widespread used in many research fields as medical physics [1,2], astronomy [3], polarizing sample characterization [4,5], among others. In all these applications, the knowledge of the state of polarization of light beams or the polarizing properties of samples is essential.…”

Study of Liquid Crystal on Silicon Displays for Their Application in Digital Holography

“…Nowadays, they are employed as Spatial Light Modulators (SLMs) in many areas, as for instance, in Optical Image Processing (Liu et al, 1985), in Holography Data Storage (Coufal et al, 2000), in Programmable Adaptive Optics (Dou & Giles, 1995), in Medical Optics (Twietmeyer et al, 2008), or in Diffractive Optics (Márquez et al, 2005), among others. Recently, a new type of reflective LCDs, the Liquid Crystals on Silicon (LCoS) displays, have awakened a great interest due to their specific technical characteristics, which in general, are superior in many aspects to the ones provided by transmissive LCDs (Lee et al, 2004;Wu & Yang, 2005).…”

Snapshot imaging Mueller matrix polarimeter using polarization gratings

“…By measuring the intensity under at least 16 unique combinations of generated and analyzed polarization states, the 16 Mueller matrix components can be calculated. However, more measurements are often taken to increase the measured signal-to-noise ratio (SNR) and to optimize the condition number of the system's measurement matrix [4,5]. Since a conventional MM imaging polarimeter uses temporal scanning, intensity variations caused by sample motion must be minimized and often require an image registration scheme [6].…”

“…As such, it has applications in ground-truth for remote sensing [2], quality control [3], and biomedical imaging [4]. A sample's MM is often characterized by time-sequentially changing the polarization state of both the generated and analyzed light using rotating polarization elements.…”