Idiopathic pleuroparenchymal fibroelastosis, a new idiopathic interstitial pneumonia: A case report.

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare disease, idiopathic in most of the cases described in the literature. We report the case of a 55-year-old patient, non-smoker with tuberculosis treated in his youth, starting with progressive dyspnoea and cough, with radiographic abnormalities consisting of pleural thickening, bronchiectasis and structural distortion predominantly in the upper lobes. Due to functional impairment and persistent radiographic abnormalities, biopsy by video-assisted thoracoscopic surgical was decided.

Performance of a q-plate tunable retarder in reflection for the switchable generation of both first- and second-order vector beams.

We examine the performance of a tunable liquid crystal q-plate in a reflective geometry. When the device is tuned to a half-wave retardance, it operates as a q-plate with twice the value (2q) by adding a quarter-wave retarder between the mirror and the q-plate. However, when the device is tuned to a quarter-wave retardance, it acts as the original q-plate without the retarder.

Analysis of a segmented q-plate tunable retarder for the generation of first-order vector beams.

In this work we study a prototype q-plate segmented tunable liquid crystal retarder device. It shows a large modulation range (5π rad for a wavelength of 633 nm and near 2π for 1550 nm) and a large clear aperture of one inch diameter. We analyze the operation of the q-plate in terms of Jones matrices and provide different matrix decompositions useful for its analysis, including the polarization transformations, the effect of the tunable phase shift, and the effect of quantization levels (the device is segmented in 12 angular sectors).