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Vilnius, Lithuania

Michailovas K.,Ekspla Ltd. | Michailovas K.,Vilnius University | Smilgevicius V.,Vilnius University | Michailovas A.,Ekspla Ltd. | Michailovas A.,Lithuanian Academy of Sciences
Lithuanian Journal of Physics | Year: 2014

A laser amplifier set-up that can be used as an effective pump source for an optical parametric chirped pulse amplification system is presented in this paper. 1-mJ 48-ps seed pulses were amplified to the energy of 80 mJ. The system operated at 1 kHz repetition rate resulting in an average output power of about 80 W. The results of enhancement of beam focusability by use of deformable mirror are presnted. © Lietuvos mokslų akademija, 2014. Source

Grishin M.,Ekspla Ltd. | Grishin M.,Lithuanian Academy of Sciences
Journal of the Optical Society of America B: Optical Physics | Year: 2011

A comparative theoretical analysis of continuously pumped actively Q-switched solid-state lasers differing in output coupling methods (cavity dumping versus a partially transmitting cavity mirror) is presented. Basic performance characteristics of the optimally coupled laser for periodic steady-state operation are expressed analytically. The instability effects are shown to fundamentally inhere in cavity dumping in contrast to ordinary Q-switching. The space of system parameters permitting stable operation and the maximum average power attainable as a train of regular energy pulses are determined numerically and verified experimentally. Cavity dumping is demonstrated to be the coupling method allowing Q-switched lasers to reach extremely high repetition rates. © 2011 Optical Society of America. Source

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2012.1.2-1 | Award Amount: 3.84M | Year: 2013

Rheumatoid arthritis (RA) and psoriasis arthritis (PSA) are destructive polyarthritic diseases having high incidence rates worldwide of about 1,5% and 0,5% respectively. Arthritis-related joint destruction leads to disabilities which result in a loss of patients quality of life, often include an inability to work and significant costs for healthcare systems. The functional outcome is strongly dependent on the time lag between the onset of the disease and the treatment beginning (ideally < 3-6 months). For early diagnosis allowing to improve the course of this devastating disease, sensitive and accurate diagnostic tools are required. Further, excellent image quality is needed for differentiated diagnosis (osteoarthritis vs RA or PSA) permitting the stratification of patient groups required for enabling a personalized therapeutical approach. Therefore, tools for early, precise and reliable diagnosis being affordable for screenings are of highest importance. Within IACOBUS, we suggest a new multimodal approach combining hyperspectral imaging with ultrasound (US) and optoacoustic (OA) techniques for diagnosis of arthritic diseases in finger joints. The proposed concept will allow the diagnosis and monitoring of arthritis based on imaging of early inflammation-induced hyperperfusion. Hyperspectral overview imaging for identification of suspicious joints will be combined with detailed high-resolution 3D imaging of affected joints (OA/US). Osteochondral information will be provided by high-frequency US while OA imaging will allow the high-sensitivity imaging of microvasculature in inflamed tissue. The consortium consisting of 4 SMEs and 3 academic partners will develop a novel non-invasive image-based diagnostic tool with significantly enhanced sensitivity for early arthritis symptoms and thereby allow to make use of the therapeutical window of opportunities. 50% of the overall project budget will go to SMEs which will ensure the exploitation of the developed platform.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ICT-2009.3.8 | Award Amount: 3.20M | Year: 2010

The project described in this proposal aims at developing a new methodology to obtain semiconductor quantum dots (QDs) regioselectively in a polymeric matrix by means of a heating probe (laser). This new method is designed to produce light emitting devices (LED/T) based on semiconductor/polymer nanocomposite emission without using lithographic processes.This type of effect is possible because, after being heated, certain types of molecules produce metal or semiconductor QDs. If this process is carried out in polymeric foil, the resulting nanocomposite can be used for several purposes. It may be particularly appealing for industrial applications since it results in conducting/semiconducting micro/nano-regions in predetermined areas of the polymer without any patterning process. The potential applications of this technology can be utilized in many fields such as memory data storage, labelling of goods and, as proposed in this project, for the construction of displays.Producing a LED/T with this methodology requires selecting several types of polymers, metal-thiolate precursors (both metal and thiol group), lasers and LED/T architectures. To simplify the concept, the whole process sequence involves material synthesis as the first step, then the formation of the polymer/precursor foil, its laser irradiation in specific regions so that only the irradiated region will be enriched with QD, and, finally, testing the LED/T.Combining the electro-optical properties of QDs, the ease of processing of polymers and the use of laser will allow for the construction of a light-emitting device (LED/T) with increased life-time as well as obtaining matrices of LED/Ts (pixels) without any patterning or inkjet processing.The expected results of this project are: i) understanding the mechanism of the nanocomposites formation in situ and its optimization and ii) the formation of LED/T with enhanced electro-optical properties (QDs) without the use of any patterning process.

Svedas V.,Lithuanian Academy of Sciences | Vaicikauskas V.,Lithuanian Academy of Sciences | Kaucikas M.,Ekspla Ltd.
Lithuanian Journal of Physics | Year: 2010

The paper analyses some equipment and methodological aspects of atmospheric pollution monitoring by infrared lidars. Features of optical parametric oscillators (including our created two-stage system) operating in the spectral ranges of molecular fundamental vibrations are discussed. The environment protection and industry demands for this remote monitoring technology are considered. Despite the progress in the technology and low detection limits achieved, the reliable and fast identification of pollutants is far from perfection. Inner and outer factors worsening the lidar performance, i. e. stability of the transmitted pulse energy, atmospheric turbulence, and irregularity of the pollutant plume near the source, are examined. A lidaric measurement model implying pulse stability was developed and applied to the 8-14 μm and 0.5 mJ per pulse lidar operating in the topographic target mode with the 0.05 m2 telescope and the mercury cadmium telluride detector. It has been found that the laser pulse energy instability (energy dispersion parameter D) essentially worsens the detection limit in shorter ranges (<2 km for D =1%). Adaptation of lidar technology to the fast varying irregular plumes was tested experimentally. Plume detection events were processed using the probabilistic model, and the probability of false alarm was evaluated. © Lithuanian Physical Society, 2010. Source

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