Optical and Acoustical Methods in Science and Technology Optical Scanner for 3D Radiotherapy Polymer Gel Dosimetry

Sophisticated techniques employed in radiotherapy for irradiation of tumours require comprehensive dosimetry allowing for precise, high resolution measurements of radiation dose distribution in three dimensions and verication of treatment planning systems. Polymer gel dosimetry has been shown to be a unique technique for such the purpose. If exposed to ionizing radiation, radical polymerisation and crosslinking of monomeric components take place in a 3D polymer gel dosimeter, leading to the formation of large polymeric structures that scatter visible light. This feature allows for optical observation of the eects of the absorbed dose and its distribution. Presently, magnetic resonance imaging is employed most often for the analysis of the 3D polymer gel dosimeters. However, much attention is also being given to the development of optical computed tomography since this technique is hoped to serve as a substitute for expensive and not easily available magnetic resonance imaging. The optical scanner presented in this work consists of a laser diode, a scanning system and a signal detector. A 3D polymer gel dosimeter is measured in an immersion liquid in order to reduce deection of the light from the dosimeter phantom. The very rst results were obtained with the newly constructed scanner and PABIG nx 3D polymer gel dosimeter, which was inhomogeneously irradiated with 192 Ir brachytherapy source. The results have been contrasted with those for the magnetic resonance imaging and are presented in this work together with the description of the developed instrument. Currently, the optimization of the optical scanner is performed

Polarimetric Optical Fiber Sensors for Dynamic Strain Measurement in Composite Materials

Polarimetric optical ber sensors possess possibility of temperature compensation, dynamic and integral system of strain monitoring, as well as low cost of photo-detecting elements. In the paper we present results of the sensor analysis with dierent kinds of birefringent optical bers leading to an optimal setup for dynamic strain monitoring in composite materials. A great attention is put on parameters of the light sources like coherence and width of spectrum and their inuence on dynamics of the strain sensor

Photonic Liquid Crystal Fibers with Polymers

Photonic liquid crystal bers with polymers constitute a new solution based on liquid crystals and microstructured polymer optical bers opening up new areas in innovative sensing and photonic devices applications. Compared with their silica-based microstructured bers, it is easier to fabricate exotic microstructured polymer optical bers by extrusion or drilling at low temperature; their nonlinearity is potentially stronger, the range of available polymers that may be drawn is more diverse and the biocompatibility of polymers is often better. Liquid crystals due to their attractive properties i.e., the high birefringence, high electro-optic and thermo-optic eects are a very good candidate for microstructured polymer optical ber inltration to obtain tunable all-in-ber innovative photonic devices. The paper will discuss basic properties and possible applications of the polymer photonic liquid crystal bers that will arise from their high optical tunability with external and internal factors. Current research eort is directed towards two main solutions: photonic crystal bers and microstructured polymer optical ber--based structures, both inltrated with liquid crystals of tailored optical properties