Ertan Kuntman

Decomposition of a depolarizing Mueller matrix into its nondepolarizing components by using symmetry conditions

A procedure for the parallel decomposition of a depolarizing Mueller matrix with an associated rank 2 covariance matrix into its two nondepolarizing components is presented. We show that, if one of the components agrees with certain symmetry conditions, the arbitrary decomposition becomes unique, and its calculation is straightforward. Solutions for six different symmetries, which are relevant for the physical interpretation of polarimetric measurements, are provided. With this procedure, a single polarimetric measurement is sufficient to fully disclose the complete polarimetric response of two different systems and evaluate their weights in the overall response. The decomposition method we propose is illustrated by obtaining the ellipsometric responses of a silicon wafer and a holographic grating from a single measurement in which the light spot illuminates sectors of both materials. In a second example, we use the decomposition to analyze an optical system in which a polarizing film is partially covered by another misaligned film.

Vector and matrix states for Mueller matrices of nondepolarizing optical media

Nondepolarizing Mueller matrices contain up to seven independent parameters. However, these seven parameters typically do not appear explicitly among the measured 16 parameters of a Mueller matrix, so that they are not directly accessible for physical interpretation. This work shows that all the information contained in a nondepolarizing Mueller matrix can be conveniently expressed in terms of a four component covariance vector state or a generating 4×4 matrix, which can be understood as a matrix state. The generating matrix, besides being directly related to the nondepolarizing Mueller matrix, mimics all properties of the Jones matrix and provides a powerful mathematical tool for formulating all properties of nondepolarizing systems, including the Mueller symmetries and the anisotropy coefficients.

Formalism of optical coherence and polarization based on material media states

The fluctuations or disordered motion of the electromagnetic fields are described by statistical properties rather than instantaneous values. This statistical description of the optical fields is underlying in the Stokes-Mueller formalism that applies to measurable intensities. However, the fundamental concept of optical coherence, that is assessed by the ability of waves to interfere, is not treatable by this formalism because it omits the global phase. In this work we show that, using an analogy between deterministic matrix states associated to optical media and quantum mechanical wavefunctions, it is possible to construct a general formalism that accounts for the additional terms resulting from the coherency effects that average out for incoherent treatments. This method generalizes further the concept of coherent superposition to describe how deterministic states of optical media can superpose to generate another deterministic media state. Our formalism of coherency is used to study the combined polarimetric response of interfering plasmonic nanoantennas.

Mueller matrix microscopy on a Morpho butterfly

The brilliant iridescent colouring in male Morpho butterflies is due to the microstrutures and nanostructures present in the wing scales, rather than pigments. In this work Mueller matrix microscopy is used to investigate the polarization properties of butterfly wing scales in reflection and transmission. It is found that the top layer of more transparent scales (cover scales) have very different polarimetric properties from the ground iridescent scales. Images with high spatial resolution showing the retarding and diattenuating optical properties for both types of scales are provided.

Mueller matrix polarimetry on a Young’s double-slit experiment analog

In this Letter we describe an experiment in which coherent light is sent through a calcite crystal that separates the photons by their polarization. The two beams are then let to superpose, and this recombined beam is used to measure the Mueller matrix of the system. Results are interpreted according to our recent formalism of coherent superposition in material media. This is the first experimental implementation of a Youngs experiment with complete polarimetry, and it is demonstrated that our method can be used for the experimental synthesis of optical devices with on-demand optical properties.

Beyond polarization microscopy: Mueller matrix microscopy with frequency demodulation

Mueller matrix microscopy is the natural generalization of polarization microscopy. It provides images of the Mueller matrix of a sample with micrometric resolution. In this work we describe a Mueller matrix microscope that uses the dual rotating compensator technique to simultaneously determine all the elements of its transmission or reflection Mueller matrix. The instrument uses two compensators that rotate at different frequencies and every Mueller matrix element is determined by using a digital frequency demodulation technique that does the frequency-analysis of the time dependent intensity captured at every pixel of the CCD detector. Transmission and reflection measurements are illustrated with experimental examples.