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1
Rozwój techniki laserowej w Polsce : 2016
Jabczyński J. K., Romaniuk R. S.
Elektronika : konstrukcje, technologie, zastosowania
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2016
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Vol. 57, nr 11
3--12
PL
Artykuł jest przeglądem prac zaprezentowanych w czasie XI Sympozjum Techniki Laserowej STL 2016 [1]. Sympozjum Techniki Laserowej jest cykliczną konferencją naukową organizowaną, co trzy lata od 1984 r. [2–8]. STL 2016, zorganizowane w tym roku przez Instytut Optoelektroniki Wojskowej Akademii technicznej [9] we współpracy z Politechniką Warszawską [10], Uniwersytetem Warszawskim [11] i Politechniką Wrocławską [12], odbyło się w Jastarni w dniach 27–30 września. Sympozjum stanowi reprezentatywny przegląd prac prowadzonych w obszarze techniki laserowej w Polsce. Prace Sympozjum STL są tradycyjnie publikowane w serii wydawniczej Proceedings SPIE od roku 1987 [13–21]. Spotkanie naukowo-techniczne zgromadziło ok. 150 uczestników którzy zaprezentowali ponad 120 artykułów badawczych i naukowo-technicznych. Sympozjum Techniki Laserowej jest miarodajnym obrazem rozwoju techniki laserowej i jej zastosowań w Polsce w laboratoriach uniwersyteckich, instytutach resortowych i rządowych, laboratoriach badawczych firm innowacyjnych, itp. Na konferencji STL prezentowane są także bieżące projekty techniczne, realizowane przez krajowe zespoły naukowe, badawcze-wdrożeniowe i przemysłowe. Zakres tematyczny Sympozjum jest tradycyjnie podzielony na dwa duże obszary – postępy techniki laserowej oraz zastosowania techniki laserowej. Nurty tematyczne Sympozjum obejmują: źródła laserowe dla bliskiej i średniej podczerwieni, lasery pikosekundowe i femtosekundowe, lasery i wzmacniacze światłowodowe, lasery półprzewodnikowe, lasery dużej mocy i ich zastosowania, nowe materiały i komponenty dla techniki laserowej, zastosowania techniki laserowej w inżynierii biomedycznej, przemyśle, inżynierii materiałowej, nano- i mikrotechnologiach, oraz metrologii.
EN
The paper is a concise digest of works presented during the XIth Symposium on Laser Technology (SLT 2016) [1]. The Symposium is organized since 1984 every three years [2–8]. SLT 2016 was organized by the Institute of Optoelectronics, Military University of Technology (IOE WAT) [9], Warsaw, in cooperation with Warsaw University of Technology (WUT) [10], Warsaw University [11], and Wrocław University of Technology [12] in Jastarnia on 27-30 September 2016. Symposium is a representative portrait of the laser technology research in Poland. Symposium Proceedings are traditionally published by SPIE [13–21]. The meeting has gathered around 150 participants who presented around 120 research and technical papers. The Symposium, organized every 3 years, is a reliable image of laser technology and laser applications development in Poland at university laboratories, governmental institutes, company R&D laboratories, etc. The SLT also presents the current technical projects under realization by the national research, development and industrial teams. The works of the Symposium, traditionally are divided in two large areas – sources and applications. The main topics of SLT were: laser sources in near and medium infrared, picosecond and femtosecond lasers, optical fiber lasers and amplifiers, semiconductor lasers, high power and high energy lasers and their applications, new materials and components for laser technology, applications of laser technology in mea surements, metrology and science, military applications of laser technology, laser applications in environment protection and remote detection of trace substances, laser applications in medicine and biomedical engineering, laser applications in industry, technologies and material engineering.
2
Content available remote Ytterbium doped phosphate glass photonic crystal fiber laser
Franczyk M., Stępień R., Pysz D., Kujawa I., Buczyński R., Jabczyński J. K.
Opto-Electronics Review
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2009
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Vol. 17, No. 3
231-235
EN
We demonstrate the 3% mol ytterbium doped phosphate glass air-clad photonic crystal fibre (PCF) laser of 43-cm length in single-mode operation. The fabrication and testing of the laser is introduced. The laser has the diameter of the core of 12 μm created in photonic microstructure and generates at wavelength of 1030 nm. Near 4-W output power and 14.6% slope efficiency against the launched pump power is demonstrated in preliminary characterization. The difference of refractive indices achieved in doped and undoped glass is Δn = 0.0004. We used the doped glass with the negative core-cladding Δn to assure the photonic crystal fibre way of single-mode propagation.
3
Content available remote Preparation and characterization of transparent Nd:YAG ceramics
Librant Z., Jabczyński J. K., Węglarz H., Wajler A., Tomaszewski H., Łukasiewicz T., Żendzian W., Kwiatkowski J.
Opto-Electronics Review
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2009
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Vol. 17, No. 1
72-77
EN
Transparent Nd:YAG ceramics were produced by solid.state reaction of high.purity (4N) nanometric oxides powders, i.e., Al₂₃O₃, Y₂₃O₃ and Nd₂₃O₃. After sintering, mean grain sizes of 2% Nd:YAG samples were about 20 µm and their transparency were a bit worse than that of 0.9% Nd:YAG single crystal. Two types of active elements: rods and slabs were fabricated and characterized in several diode pumping schemes. In end pumping configuration as a pump source 20.W fiber coupled laser diode operating in low duty cycle regime (1 ms pump duration/20 Hz) was deployed. In the best case, 3.7 W of output power for 18 W of absorbed pump power, M ² < 1.4 were demonstrated for uncoated ceramics Nd:YAG rod of Φ 4×3mm size in preliminary experiments. For the ceramics of two times lower Nd dopant level above 30% slope efficiency was achieved. In case of Nd:YAG ceramic slab side pumped by 600.W laser diode stack above 12 W was demonstrated with slope efficiency of 3.5%.
4
Content available remote Intracavity optical parametric oscillator pumped by passively Q-switched Nd:YLF laser
Żendzian W., Jabczyński J. K., Kwiatkowski J.
Opto-Electronics Review
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2009
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Vol. 17, No. 1
45-52
EN
We report on a passively Q-switched end pumped Nd:YLF laser including a noncritically phase-matched KTP singly resonant intracavity optical parametric oscillator (IOPO-KTP). For the Q-switching operation we have used Cr:YAG saturable absorber. The optimized passively Q-switched Nd:YLF laser without IOPO generated linearly polarized pulses of 11.5 ns and 1.07 mJ at 1047 nm. The conversion efficiency of the optimized Q-switched pulse energy at 1047 nm to 1547 nm of a signal approached about 47%. For optimizing both Nd:YLF laser and IOPO we have numerically solved a theoretical model. We have achieved 1.6-ns duration pulses at 1547 nm with energy of 0.5 mJ and peak power of above 300 kW. The beam quality was excellent (M ² ≈ 1).
5
Content available remote High repetition rate, tunable, Q-switched diode pumped Tm:YLF laser
Gorajek Ł., Jabczyński J. K., Żendzian W., Kwiatkowski J., Jelinkova H., Sulc J., Nemec M.
Opto-Electronics Review
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2009
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Vol. 17, No. 4
309-317
EN
The aim of work was to characterize a simple oscillator consisted of Tm:YLF crystal end-pumped by a fiber coupled diode laser and active Q-switch with tunability option. About 7 W with near 35% slope efficiency was demonstrated in a free-running mode. The divergence angle was about 4.3 mrad and estimated parameter M² < 1.3. Continuous tuning by means of Lyot's filter, consisted of 2 quartz plates in the range of 1879.0-1939.4 nm with less than 1-nm linewidth, was achieved. For the best case (10-ms pump pulse duration, 42-A pump current corresponding to 266 mJ of pump energy) , the Q-switched energy was 10.5 mJ with pulse duration of 22 ns corresponding to near 0.5 MW peak power. The 2.5 W of average power with 12.6-kW peak power and 2000-Hz repetition rate was demonstrated for cw pumping regime.
6
Content available remote CW mode locked Nd:YVO₄ laser pumped by 20-W laser diode bar
Jabczyński J. K., Żendzian W., Kwiatkowski J.
Opto-Electronics Review
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2006
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Vol. 14, No. 2
135-139
EN
The efficient cw mode locking (cw-ML) regime was demonstrated in Nd:YVO₄ laser by means of saturable absorber mirror (SAM). The 0.3-at.% Nd³⁺ doped 10-mm-long YVO₄ crystal end pumped by 20-W diode module with a beam shaper was applied as a gain medium located in the close vicinity to the rear flat mirror of the first arm of Z-type resonator of 316 cm total length with two curved mirrors of 100-cm curvature radii. The SAM of 2%-saturable absorptance and saturation fluence of 50 μJ/cm² was mounted at the opposite end of a resonator. The developed “dynamically stable” cavity design mitigates detrimental role of thermal aberration in gain medium, enforcing clean perfect mode locking even for the highest pump densities. The cw-ML pulses with 47.5 MHz repetition rate and pulse durations in the range of 15–20 ps were observed for a wide range of pump powers and output coupler losses. In the best case, for 32% of output coupler transmission, up to 6.2 W of average power with near 35% slope efficiency was achieved. The thresholds for Q-switched ML, cw-ML regimes were 2.67 W and 6.13 W of pump power, respectively. For the maximum pump power of 20 W we obtained 133 nJ of pulse energy with 16-ps pulse duration, resulting in a peak power higher than 8 kW. The threshold energy density at SAM giving the QML regime was estimated to be about 30 μJ/cm2, threshold of cw-ML regime was 220 μJ/cm².
7
Content available remote Thermo-optic effects in solid state lasers end-pumped by fiber coupled diodes
Jabczyński J. K., Jaguś J., Żendzian W., Kwiatkowski J.
Opto-Electronics Review
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2005
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Vol. 13, No. 1
69--74
EN
Review of thermo-optic effects in gain media of diode pumped lasers is presented. Methods of modelling and compensation of such effects are discussed. Results of characterization of end-pumped lasers by means of energetic and caustics measurement techniques are presented and discussed. Also application of Wigner distribution method for characterization of aberrated laser beams is discussed. Thermally induced astigmatism was observed for the anisotropic rods at high heat load.
8
Content available remote Q-switched mode locking in diode pumped lasers
Jabczyński J. K., Żendzian W., Kwiatkowski J.
Opto-Electronics Review
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2005
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Vol. 13, No. 4
317-323
EN
The Q-switched mode locking (QML) regime provides the generation of relatively high peak power picosecond pulses train with energies of a few µJ each in a simple resonator. The critical review of QML methods and results including our investigations is given in the first part of presentation. The application of several types of saturable crystalline absorbers (Cr⁴⁺:YAG, V³⁺:YAG, LiF, GaAs) leads to chaotic, partial QML effect, with less than 100% modulation depth in principle. The fully modulated efficient QML laser was demonstrated in the next part. The acousto-optic cell playing a double role of Q-switch and mode locker was located near a flat output coupler. The two folding mirrors were mounted on the translation stages for matching the resonance frequency of the cavity to the radio frequency of acousto-optic modulator. The QML pulses with envelope durations of 100n150 ns and 100% modulation depth were observed for wide range of pump powers and repetition rates. In the preliminary experiments up to 3 W of output average power, 100 µJ of the envelope energy, having approximately 5n8 mode locked pulses were achieved.
9
Content available remote Application of Wigner transform for characterization of aberrated laser beams
Jaguś J., Jabczyński J. K., Żendzian W., Kwiatkowki J.
Optica Applicata
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2005
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Vol. 35, nr 1
33-41
EN
The slit scan method was implemented for registration of intensity profiles along the caustics of a laser beam. The inverse Radon transform of spatialy normalized intensity profiles enables direct computation of Wigner transform of real laser beam. The Rayleigh range, divergence angle, beam quality factor, global degree of coherence can be determined in such a simple way. A procedure enabling derivation of the shape of aberrated wavefornt and spherical aberration content was elaborated. This method was applied for investigation of the aberrated laser beams generated by cw and pulsed diode pumped laser.
10
Content available remote Measurement of Q-Switching & Mode Locking in diode pumped Nd:YVO₄ laser with passive saturable absorbers
Kwiatkowski J., Jabczyński J. K., Żendzian W.
Biuletyn Wojskowej Akademii Technicznej
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2005
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Vol. 54, nr 11
35-41
EN
The saturable absorbers (Cr⁴⁺:YAG, GaAs and LiF crystals for 1064 nm wavelength, V³⁺:YAG crystals for 1340 nm respectively) were examined as passive Mode Lockers and Q-switches in diode pumped Nd:YVO₄ lasers in the Z-type resonators. In each case, partially modulated long trains of QML pulses were observed. As a rule, envelopes with about 1 µs duration and more than 50% depth of modulation were observed. For stabilization of the mode locking trains the nonlinear crystals (KTP or LBO) as negative feedback elements were inserted. The fully modulated QML trains for intracavity II harmonic conversion at 670 nm wavelength in V³⁺:YAG Q-switched Nd:YVO₄ laser with LBO crystal were demonstrated.
PL
W artykule przedstawiono wyniki badań lasera Nd:YVO₄ pracującego w konfiguracji rezonatora typu "Z" z pasywnymi modulatorami dobroci (Cr⁴⁺:YAG, GaAs oraz LiF na długości fali generacji 1064 nm, V³⁺:YAG na dlugości fali 1340 nm). Obserwowano impulsy laserowe z synchronizacją modów o czasie trwania obwiedni około 1 µs i głębokości modulacji powyżej 50%. W celu polepszenia stabilności synchronizowanych modów jako ujemne sprzężenie wykorzystano nieliniowy element w postaci kryształu KTP lub LBO. Zaobserwowano pełną głębokość modulacji promieniowania o długości fali 670 nm w laserze Nd:YVO₄ z przełącznikiem dobroci V³⁺: YAG z przetwarzaniem na II harmoniczną za pomocą kryształu LBO.
11
Content available remote Optical characterization of diode side pumped active elements
Jabczyński J. K., Kwiatkowski J., Żendzian W.
Optica Applicata
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2003
|
Vol. 33, nr 2-3
421-431
EN
A numerical model of side pumped gain elements of rod or slab shape enabling estimation of overlapping efficiency and threshold was developed. This model was applied for analysis and optimization of laser heads side pumped by a single diode bar. The diode side pumped lasers heads for Nd:YAG rod and slab active elements were designed and characterized under real pumping conditions with a 40-W diode bar. The optical performance of both types of heads was shown experimentally to be delimited by transversal, asymmetrical thermal gradients resulting in high level of depolarization and diffraction losses. The fundamental mode limit is about 20 W per 1 cm for a head side pumped by a single diode bar
12
Content available remote Laser beam propagation in gain media of diode pumped lasers
Jabczyński J. K., Kwiatkowski J., Żendzian W.
Optica Applicata
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2003
|
Vol. 33, nr 2-3
411-420
EN
Two models of gain and thermal guiding effects were derived. In the first one, the complex ABCD matrix for a crystal under gain and thermal guiding was applied to describe the operation of microchip near threshold. In the second one, a simple iterative procedure was proposed to calculate effective fundamental mode parameters of a cavity under thermal and gain guiding for given bare cavity ABCD matrix and pumping parameters, including gain saturation, passive cavity losses and reabsorption ones. The influence of gain guiding effects causes changes of waist width in the range up to 50% compared to expectations derived from thermal guiding theory. Application of such a method for resonators of passively Q-switched lasers was proposed. Results of calculations for microchips were verified with experiment.
13
Ocena sprawności generacji głowic laserowych w schemacie pompowania bocznego
Kwiatkowski J., Jabczyński J. K., Żendzian W., Świderski J.
Elektronika : konstrukcje, technologie, zastosowania
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2003
|
Vol. 44, nr 8-9
43-45
PL
Opracowano model teoretyczny i oszacowano eksperymentalnie optymalne geometrie lasera w schemacie pompowania bocznego. Zbudowano głowice przeznaczone dla różnych typów ośrodków czynnych: cylindrycznych prętów, trójkątnych, trapezowych i prostopadtościennych sztabek. Przeprowadzono badania termograficzne w celu określenia rozkładów temperatur ośrodków czynnych pod dużym obciążeniem cieplnym. Badano aberracje termiczne, stan depolaryzacji, kontrast i straty depolaryzacyjne ośrodków czynnych pompowanych diodą pracy ciągłej o mocy do 40 W. Zmierzono charakterystyki energetyczne ww. głowic w rezonatorach o krótkiej bazie i stwierdzono istotne aberracje depolaryzacyjne ograniczające pracę lasera w podstawowym modzie poprzecznym do mocy pompowania około 20 W. Uzyskano maksymalnie do 8 W mocy wiązki wyjściowej o asymetrycznej rozbieżności z M²~2x10.
EN
Model of side pumped laser elements of rood or slab shaped enable us to estimate of overlapping efficiency and threshold. The diode side pumped lasers heads for rod and slab active elements were elaborated and characterized under real pumping conditions. It was shown in experiments that the optical performance for both types of heads is delimited by transversal asymmetrical thermal gradients which results in high level of depolarization and diffraction losses. Thermal aberrations, level of depolarization, extinction ratio and depolarization losses of active element were investigated.
14
Content available remote Generator parametryczny pompowany wewnątrz rezonatora lasera Nd:YAG z pasywną modulacją dobroci
Żendzian W., Jabczyński J. K., Kwiatkowski J.
Biuletyn Wojskowej Akademii Technicznej
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2002
|
Vol. 51, nr 6
5-20
PL
W artykule przedstawiono ednorezonansowy generator parametyczny z kryształem KTP pompowany wewnątrz rezonatora lasera Nd:YAG z pasywną modulacją dobroci pobudzanego 300 W diodą quasi ciągłego działania. Uzyskano ze sprawnością całkowitą 3,8% impulsy na długości fali 'Bezpiecznej dla wzroku" ʎ = 1572nm, o energii 1,9 mJ i czasie trwania 2,8 ns, generowane z częstotliwością 100 Hz. Przedstawiono również model teoretyczny wewnątrzrezonatorowo pompowanego generatora parametrycznego IOPO, bazujący na równaniach kinetycznych lasera z pasywnym modulatorem dobroci rezonatora i równaniach kinetycznych generatora parametrycznego. Uzyskano dobrą zgodność wykonanych obliczeń przebiegów czasowych generacji IOPO z wynikami eksperymentalnymi. Zarówno eksperymentalnie, jak i teoretycznie wykazano dużą prawność IOPO.
EN
It is presented a single resonance parametric generator with KTP crystal pumped in the intracavity of Nd:YAG laser with Q-factor passive modulation. The generator was excited using 300 W quasi-continuous operated diode. The pulses were obtained of 3,5% total effeciency and eyesafe wavelenght ʎ = 1572 nm of energy 1.9 mJ and duration 2.8 ns generated with frequency 100 Hz. A theoretical model of the intracavity pumped the IOPO parametric generator is also presented based on the kinetic equations of the laser with passive modulator of cavity Q-factor and kinetic equations of parametric generator. A good coincidence of the time courses of the IOPO generation with experimental results is obtained. alarge efficiency of the IOPO was found in the experiments as well as theoretically.
15
Content available remote Investigation on passively Q-switched Nd:YAG slab laser pumped by 2D quasi cw diode laser stack
Żendzian W., Jabczyński J.K., Mierczyk Z.
Opto-Electronics Review
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2001
|
Vol. 9, No. 1
75-81
EN
The paper presents results of investigations on generation of Nd:YAG triangle slab laser pumped by 2D diode array. The pump beam shape quality with respect to pump/mode overlap efficiency was investigated both theoretically and experimentally. Two cavity schemes with and without pump forming optics were verified in free running and passively Q-switching modes. Slope efficiency of 45% and output energy of 24 mJ for incident 60 mJ of pump energy were achieved in free running mode. Applying Cr⁴⁺:YAG crystal as passive Q-switch, the output energy of 5 mJ and 0.5 MW peak power were obtained in the optimised resonator.
16
Content available remote High repetition rate, V³⁺:YAG crystal Q-switched diode pumped Nd lasers
Jabczyński J. K., Mierczyk Z., Żendzian W., Kopczyński K., Frukacz Z.
Opto-Electronics Review
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2001
|
Vol. 9, No. 1
57-66
EN
The high repetition rate passively Q-switched neodymium host lasers operating at 1 mm wavelenght pumped by a 10-W fibre-coupled diode laser are presented. As a passive q-switch the V³⁺:YAG crystal was applied. The V³⁺:YAG parameters were determined in spectroscopic and saturable transmission experiments. A numerical model taking into account short recovery time of V³⁺:YAG ~ 5 ns and excited state absorption was used to analyse such a laser. The thermal lensing magnitude and performance were determined in free running experiments for two Nd:YAG rods of different quality and Nd:YLF crystal. The smooth Q-switched pulses with repetition rates of 40-200 kHz were abtained in short linear cavities of a length less than 11cm. The highest average power of 1.4 W with slope efficiency of 20% was demonstrated in Nd:YAG laser. Long pulse durations of hundreds ns and low pulse energy of a few mJ (up to 24 in the best case) were caused by low value of the ratio of the absorption cross section of V³⁺:YAG to emission cross section of Nd:YAG. The much higher pulse energy of 70 µJ with pulse duration of 80 ns was abtained in lower gain Nd:YLF laser in a cavity of 140 mm length with internal lens 50 mm focal length.
17
Content available remote Modelling of laser pumped intracavity frequency doubled laser.
Jabczyński J.K.
Optica Applicata
|
2000
|
Vol. 30, nr 1
161-171
EN
A model of an intracavity frequency doubled laser pumped by a laser beam was elaborated. The effects connected with mode matching, thermal lensing, pump induced diffraction losses, as well as parameters of frequency conversion and geometry of cavity were considered. An analytical model of the cavity with an internal lens and thermal lensing was derived to optimize output characteristics. Two types of cavity (with and without internal lens) were analyzed and the best configurations with respect to second harmonic output power were found for both cases. The pump induced diffraction losses were found to limit the output power of the frequency doubled laser for high pump levels.
18
Content available remote Growth and optical properties of Nd:YVO₄ laser crystals
Kaczmarek S. M., Łukasiewicz T., Giersz W., Jabłoński R., Jabczyński J. K., Świrkowicz M., Gałązka Z., Drozdowski W., Kwaśny M.
Opto-Electronics Review
|
1999
|
Vol. 7, No. 2
149-152
EN
Growth conditions for Nd:YVO₄ crystals and some optical properties are presented. The obtained Nd:YVO₄ crystal shows lower content of point defects and consequently, lower susceptibility to ionising radiation. ESR measurements show the presence of V ions in intersitial sites with another than 5t valency. Obtained by Czochralski method crystals reveal very good optical properties, some of which are better than for Nd:YAG.
19
Content available remote Thermally induced pulsation in the solid-state single-frequency diode pumped laser.
Peshko I., Jabczyński J. K.
Optica Applicata
|
1999
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Vol. 29, nr 3
319-325
EN
Slow, periodical self-modulation phenomena in the diode-pumped single-modulation phenomena in the diode-pumped single-frequency Nd:YVO4 laser with cobalt thin-film selector have been demonstrated. The pulses duration about 1-3 s and period about 3-10 s, depending on pump power and thermooptical properties of cavity, have been observed. The effect has been explained by the thermal changes of the cavity length connected with the difference of the heat generation rate for operating and non-operating laser.
20
Content available remote Investigations of cavity losses in diode pumped lasers.
Jabczyński J.K., Kopczyński K., Marciniak P.
Optica Applicata
|
1998
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Vol. 28, nr 3
191-199
EN
Two methods of losses measurements: Findlay-Clay's method and relaxation frequency method were verifield for two types of diode pumped lasers. In the case of Nd: YAG laser with changeable output coupler, the results obtained for both methods were in good agreement. However, there was observed a contradiction between the relatively high losses (about 10% for transmission losses of 5% and very high slope efficiency (~50%) of this laser. The measurements of cavity losses via relaxation method were carried out for several types of microlasers made of Nd:YAG, Ng:GGG, Nd:YAP crystals and Nd:phosphate glass. There were obtained total losses (including transmission ones) on the range from 7% to 30%.
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