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Your search keyword '"Jelinkova, Helena"' showing total 285 results
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285 results on '"Jelinkova, Helena"'

1. High power single crystal KTA optical parametric amplifier for efficient 1.4-3.5 $\mu$m mid-IR radiation generation

Author

Csanaková, Bianka, Novák, Ondřej, Roškot, Lukáš, Mužík, Jiří, Smrž, Martin, Jelínková, Helena, and Mocek, Tomáš

Subjects
Physics - Optics
Abstract

In this paper, we present a single crystal, KTA (potassium titanyl-arsenate, KTiOAsO$_4$) based picosecond optical parametric amplifier pumped by an in-house built 1030 nm Yb:YAG thin-disk laser, capable of tunability from 1.46 to 3.5 $\mu$m, operating at 90 kHz, with high average power in the signal and idler beams. The highest output power of 8.9 W was reached for the 1750 nm signal beam with 19% conversion efficiency and the respective 2500 nm idler beam power was 6.2 W with 13% efficiency. The highest combined signal and idler mid-IR power was obtained at 17 W at the 2060 nm wavelength degeneracy point., Comment: 8 pages, 14 figures

Published
2024
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20. Widely tunable Tm3+:LuF3-CaF2 diode pumped laser

Author

Veselsky, Karel, primary, Sulc, Jan, additional, Jelinkova, Helena, additional, Doroshenko, Maxim E., additional, Pierpoint, Kseniia A., additional, Konyushkin, Vasilii A., additional, and Nakladov, Andrey N., additional

Published
2021
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27. Penetration of high-intensity Er:YAG laser light emitted by IR hollow optical fibers with sealing caps in water

Author

Iwai, Katsumasa, Shi, Yi-Wei, Endo, Masashi, Ito, Kentaro, Matsuura, Yuji, Miyagi, Mitsunobu, and Jelinkova, Helena

Subjects
Optics -- Research, Astronomy, Physics
Abstract

The penetration depth in water was measured for Er:YAG laser light in a high density relevant to clinical applications. Various types of focusing elements were used to guide the light efficiently. We found that the transmission distance depended strongly on the beam shape in the water. When we used a plano-convex type of focusing cap, the penetration depth was larger than that when a dome- or ball-type cap were used. OCIS codes: 120.4820, 140.3500, 230.7370, 170.3890.

Published
2004

28. Erbium:YAG laser lithotripsy by use of a flexible hollow waveguide with an end-scaling cap

Author

Iwai, Katsumasa, Shi, Yi-Wei, Nito, Koh, Matsuura, Yuji, Kasai, Takao, Miyagi, Mitsunobu, Saito, Seichi, Arai, Youichi, Ioritani, Naomasa, Okagami, Yoshihide, Nemec, Michal, Sulc, Jan, Jelinkova, Helena, Zavoral, Miroslav, Kohler, Oto, and Drlik, Pavel

Subjects
Lithotripsy -- Technology application, Lithotripsy -- Equipment and supplies, Lasers in medicine -- Technology application, Technology application, Astronomy, Physics
Abstract

An Er:YAG laser light delivery system composed of a polymer-coated silver hollow waveguide and a quartz sealing cap has been developed for calculus fragmentation. Sealing caps with various distal-end geometries were fabricated, and the focusing effects of these caps for Er:YAG laser light were measured both in air and in water. Owing to the high power capability of the quartz sealing caps, a beam of Er:YAG laser light with an output energy of 200 mJ and a repetition rate of 10 Hz was successfully transmitted in saline solution by use of the system. Calculus fragmentation experiments conducted in vitro showed that the delivery system is suitable for medical applications in lithotripsy. We also found that the cap with a focusing effect is more effective in cutting calculi. The deterioration of the sealing caps after calculus fragmentation is also discussed. OCIS codes: 140.3070, 160.5470, 230.7370, 170.7230, 170.1610.

Published
2003

29. Actively Q-switched Thulium Lasers

Author

K., Jan, primary, Gorajek, Lukasz, additional, Zendzian, Waldemar, additional, Kwiatkowski, Jacek, additional, Jelinkova, Helena, additional, Sulc, Jan, additional, and Nemec, Michal, additional

Published
2010
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31. Highly efficient picosecond Raman generators based on the BaWO[subscript 4] crystal in the near infrared, visible, and ultraviolet

Author

Cerny, Pavel, Jelinkova, Helena, Basiev, Tasoltan T., and Zverev, Peter G.

Subjects
Solid-state lasers -- Research, Raman effect -- Research, Laser pulses, Ultrashort -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

Highly efficient stimulated Raman scattering of near-infrared, visible, and UV picosecond laser plses in BaWO[subscript 4] crystals is investigated and discussed. Single-pass, double-pass, and Raman cavity configurations are used.

Published
2002

35. Tm3+:LuF3-CaF2 Diode Pumped Laser in 1.9 μm Region

Author

Veselsky, Karel, primary, Sulc, Jan, additional, Jelinkova, Helena, additional, Doroshenko, Maxim E., additional, Pierpoint, Kseniia A., additional, Konyushkin, Vasilii A., additional, Nakladov, Andrey N., additional, and Osiko, Vjatcheslav V., additional

Published
2019
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44. Two wavelength satellite laser ranging using SPAD

Author

Prochazka, Ivan, Hamal, Karel, Jelinkova, Helena, Kirchner, Georg, and Koidl, F

Subjects
Lasers And Masers
Abstract

When ranging to satellites with lasers, there are several principal contributions to the error budget: from the laser ranging system on the ground, from the satellite retroarray geometry, and from the atmosphere. Using a single wavelength, we have routinely achieved a ranging precision of 8 millimeters when ranging to the ERS-1 and Starlette satellites. The systematic error of the atmosphere, assuming the existing dispersion models, is expected to be of the order of 1 cm. Multiple wavelengths ranging might contribute to the refinement of the existing models. Taking into account the energy balance, the existing picosecond lasers and the existing receiver and detection technology, several pairs or multiple wavelengths may be considered. To be able to improve the atmospheric models to the subcentimeter accuracy level, the differential time interval (DTI) has to be determined within a few picoseconds depending on the selected wavelength pair. There exist several projects based on picosecond lasers as transmitters and on two types of detection techniques: one is based on photodetectors, like photomultipliers or photodiodes connected to the time interval meters. Another technique is based on the use of a streak camera as an echo signal detector, temporal analyzer, and time interval vernier. The temporal analysis at a single wavelength using the streak camera showed the complexity of the problem.

Published
1993

45. Satellite laser station Helwan status 1992

Author

Cech, M, Hamal, Karel, Jelinkova, Helena, Novotny, Antonin, Prochazka, Ivan, Baghos, B. B, Helali, Y, and Tawadros, M. J

Subjects
Ground Support Systems And Facilities (Space)
Abstract

The Satellite Laser Station Helwan has been operated jointly by the National Research Institute of Astronomy and Geophysics in Helwan, Egypt and the Czech Technical University in Prague, Czechslovakia. The station components have been carefully tuned to increase the systems overall stability and reliability critical for the remote location. The mount correction model based on the Gaussian smoothing has been implemented to simplify the blind satellite acquisition and tracking. The on-site normal points generation algorithm has been implemented, the station has been connected to the international information network. The ERS-1 satellite has been included into the tracking schedule. The station range capability has been verified by experimental Etalon 1 ranging by April 1992. The ranging precision of 2-3 centimeters is obtained when ranging to ERS-1, Starlette, and Lageos satellites.

Published
1993

46. New methods of generation of ultrashort laser pulses for ranging

Author

Jelinkova, Helena, Hamal, Karel, Kubecek, V, and Prochazka, Ivan

Subjects
Lasers And Masers
Abstract

To reach the millimeter satellite laser ranging accuracy, the goal for nineties, new laser ranging techniques have to be applied. To increase the laser ranging precision, the application of the ultrashort laser pulses in connection with the new signal detection and processing techniques, is inevitable. The two wavelength laser ranging is one of the ways to measure the atmospheric dispersion to improve the existing atmospheric correction models and hence, to increase the overall system ranging accuracy to the desired value. We are presenting a review of several nonstandard techniques of ultrashort laser pulses generation, which may be utilized for laser ranging: compression of the nanosecond pulses using stimulated Brillouin and Raman backscattering; compression of the mode-locked pulses using Raman backscattering; passive mode-locking technique with nonlinear mirror; and passive mode-locking technique with the negative feedback.

Published
1993

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