Category: Uncategorized

Optical activity in reflection

When I was a PhD student I remember  I often wondered  why circular dichroism (CD) was measured only in transmission.  At that time I was already familiar with ellipsometry measurements (in reflection) that are typically used to determine the dielectric function of materials and I did not understand why optical activity, arguably also a optical property…

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A note on optical activity and extrinsic chirality

“Optical activity produces a differential absorption or refraction according to the handedness of circular polarized light, but the inverse is not necessarily true: a differential absorption of refraction of circular polarized light does not imply optical activity” This simple statement has been sometimes overseen and there exist some confusion among researchers studying optical activity in several fields of…

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Tutorial on Mueller matrix ellipsometry

This week I participated in the 9th Workshop on Ellipsometry hosted by the University of Twente in Enschede, the Netherlands. I was invited there to give a tutorial talk on Mueller matrix polarimetry. Here you can download the slides of the presentation  in PPTX or PDF formats.

Evolving Mueller matrix microscopy

For over a year and a half I have been working on Mueller matrix microscopy.  Now I can say that I have no doubts that, when it is properly implemented, Mueller matrix microscopy is nothing but the perfect upgrade for polarization microscopy. I know polarization microscopy is not the most trendy technique in these days, but polarization…

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Happy New International Year of Light

It is time to welcome 2015. This New Year should be specially interesting for us since it is the International Year of Light and Light-based Technologies. The International Year of Light is a global initiative adopted by the United Nations to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in…

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Summary of last activities

In the last few months a good part of my research has been about Mueller matrix microscopy.  We have developed a new MM microscope that uses a dual rotating compensator setup and digital demodulation.  The spatial resolution and measurement quality is really good. See related publications here and here. This week we have published a…

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Analytic interpretation of Mueller matrices based on a continuous medium description

For some reason I cannot fully understand, certain types of serial decompositions of Mueller matrices became quite popular among experimentalists. I am talking about the polar decomposition and the Lu-Chipman decompositions. These matrix decompositions allow to decompose a matrix in a series of a retarder, a diattenuator and, eventually, also a depolarizer. Of course matrix…

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Setember update

Not many updates lately! I hope this semester I will manage to  keep the website more up-to-date.  I also want to add a section with some  new scientific content in the form of a tutorial, let’s see if I find the time. For the moment today I have updated the publication list in the lazy…

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