The paper focuses on two families of instruments that have been developed over several years in the Institute of applied Optics using microinterferometric and confocal approach. The continuously variable light source constitutes the binding element of these two classes of measuring devices. The light source has to emit continuous spectrum. During measurements the selected wavelength must be determined with significant accuracy, which constitutes the key and critical factor of the measurement process as a whole. The described systems are only a small part of what photonics offers but are very useful in characterizing many objects and materials in research and industrial environment.
The phenomenon of laser light scattering provides the technology for visualization and testing the inner structure and homogeneity of materials. Some of them excited by the laser light in the tomographic process can emit light the wavelength of which is different than that of excitation laser. Such photoluminescence can be a source of additional information of the material’s structure. Combining the Laser Scattering Tomography (LST) and Spectrometry techniques has enabled us to develop a new type of an LST technique. The system is useful for investigations of various materials like semiconductors (Si, GaAs) ceramics, crystals for passive absorbers for high power pulse lasers, and laser crystals.
The automotive industry has been always a driving force for all economies. Despite of its beneficial meaning to every society it brings also many issues including wide area of road safety. The latter has been enforced by the increasing number of cars and the dynamic development of the traffic as a whole. Road signs and traffic lights are crucial in context of good traffic arrangement and its fluency.<p> </p>Traffic designers are used to treat horizontal road signs independently of vertical signs. However, modern light sources and growing flexibility in shaping optical systems create opportunity to design more advanced and smart solutions. In this paper we present an innovative, multidisciplinary approach that consists in tight interdependence of different traffic signals. We describe new optical systems together with their influence on the perception of the road user. The analysis includes maintenance and visibility in different weather conditions. A special attention has been focused on intersections of complex geometry.
We present the study of potential application of Cavity Enhanced Absorption Spectroscopy (CEAS) for
construction of fully optoelectronic and portable NO<sub>2</sub> detector which could replace the commonly used chemical
detectors. We demonstrate an experiment on detection of NO<sub>2</sub> in the ambient air. The concentration of investigated
absorber was found by determination of decay time of pulse radiation trapped in the optical cavity constructed with two
mirrors of a very high reflectivity coefficient (R > 99,99%). As a light source a blue pulsed diode laser was applied. The
output signal was detected by a photomultiplier and analysed by a digital oscilloscope. For this construction the detection
limit better than 1 ppb was obtained. The cavity parameters and it's adjustment were controlled by a beam from a red
laser that is not absorbed by NO<sub>2</sub>. In order to perform the measurements in two spectral regions the special mirrors have
been developed. Study of influence of another NO<sub>x</sub> compounds (especially NO<sub>3</sub>) on final result was investigated as well.
The examination of quality of the sperm ejaculate is one of the most important steps in artificial fertilization procedure. The main aim of semen storage centres is to characterise the best semen quality for fertilization. Reliable information about sperm motility is also one the most important parameters for <i>in vitro</i> laboratory procedures. There exist very expensive automated methods for semen analysis but they are unachievable for most of laboratories and semen storage centres. Motivation for this study is to elaborate a simple, cheap, objective and repeatable method for semen motility assessment. The method enables to detect even small changes in motility introduced by medical, physical or chemical factors. To test the reliability of the method we used cryopreserved bull semen from Lowicz Semen Storage Centre. The examined sperm specimen was warmed in water bath and then centrifuged. The best semen was collected by the swim-up technique and diluted to a proper concentration. Several semen concentrations and dilutions were tested in order to find the best probe parameters giving repeatable results. For semen visualization we used the phase-contrast microscope with a CCD camera. A PC computer was used to acquire and to analyse the data. The microscope table equipped with a microscope glass pool 0.7mm deep instead of some conventional plane microscope slides was stabilised at the temperature of 37°C. The main idea of our method is based on a numerical processing of the optical contrast of the sperm images which illustrates the dynamics of the sperm cells movement and on appropriate analysis of a grey scale level of the superimposed images. An elaborated numerical algorithm allows us to find the relative amount of motile sperm cells. The proposed method of sperm motility assessment seems to be objective and repeatable.
We present an experiment on detection of nitrogen dioxide in free air using cavity enhanced spectroscopy. As a light source a blue pulsed diode laser was applied, while the output signal was detected with a photomultiplier. The absorber concentration was found by investigation of the optical resonator quality. It was done by determination of decay time of radiation pulse trapped in the cavity. Also the measurement of the phase shift between the output signal and modulation signal was used as the alternative method. The detection limit better than 1 ppb was demonstrated. The aim of this experiment was to study potential application of cavity enhanced absorption spectroscopy for construction of fully optoelectronic NO<sub>2</sub> detector which could replace the commonly used chemical detectors.