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High peak-power picoseconds laser pulses generation at aberrational lens and gain saturatingтезисы доклада
- Авторы: Morozov V.B., Olenin A.N., Yakovlev D.V.
- Сборник: 27st International Laser Physics Workshop LPhys'18
- Серия: LPhys
- Том: 1
- Тезисы
- Год издания: 2018
- Место издания: IOP Pub. Ltd Bristol, UK, England
- Первая страница: S4.1.2
- Последняя страница: S4.1.2
- Аннотация: Picosecond lasers with single pulse energy of up to multi-mJ level operating at sub-kHz repetition rates are required in a number of scientific and technological applications, such as time-resolved laser spectroscopy, ablation study, precise satellite laser ranging, driving photoinjectors etc. Despite the peak power of GW fractions, average power amounts only few W and then the schemes based on diode pumped bulk crystals are most appropriate. In this paper, we consider schematic solutions of such kind energy-effective, compact and easy integrated picoseconds lasers based on Nd-doped crystals. We develop approach based on the dynamical operation control scheme utilizing pulsed repetitive pumping, active and passive mode-locking, negative feedback in the oscillator cavity, regenerative and transient amplifying stages [1,2]. This provides laser pulse formation in each laser shot and actually allows shortest way for obtaining just at the laser output hig-peak-power and near transform limited picosecond pulses of several mJ energy with excellent pulse-to-pulse stability and low optical jitter value [3]. Evolution of pulse energy, spectrum and time profile during a single generation cycle is well illustrated using universal numerical calculation model which describes pulse formation governed by the operation control and also taking into account the pulse profile modifying due to amplification [2]. Diode end-pump geometry gives maximal overlapping of resonator mode and pumped volume, whereby allowing optimal pump energy utilizing into the output radiation. As a result, using the picosecond Nd:YAG laser based on the described scheme with one end-amplifier stage provides 25 ps pulses more than 5 mJ at fundamental wavelength with repetition rates up to 400Hz. Conversion efficiency in the second harmonic with LBO nonlinear crystals is above 60\%. Owing to pulse-repetitive regime and end-pump geometry, thermal loading is the heat load is as low as possible and the system cannot require liquid cooling and is easily power scalable by means of an additional amplification stage operating near the saturation regime. At high repetition rates operation conditions strongly depend on thermal lens induced in the laser crystal [4]. Increase of average end-pump power principally results in aberrational lens formation which may influence on mode locking and pulse amplification regime. Effective lasing and mode-locking at aberrational thermal lens condition is important for the development of practical and robust laser systems. Thermal lens and mode structure at end-pump geometry were analyzed using non-Gaussian mode decomposition into Laguerre-Gaussian beams with the width equal to the embedded beam value. We considered regime at which adaptive action of the aberration lens might enhance the resonator stability range. Detailed experimental and modeling results are presented. \\ \ [1] M.V.Gorbunkov, \ \ A.V.Konyashkin, \ \ P.V.Kostryukov, \ \ V.B.Morozov, \ A.N.Olenin, \ V.A.Rusov, \\ L.S.Telegin, V.G.Tunkin, Yu.V.Shabalin, D.V.Yakovlev. Pulsed-diode-pumped, all-solid-state, electro-optically controlled picosecond Nd:YAG lasers. Quantum Electron., 35 (1), 2-6 (2005)
- Добавил в систему: Морозов Вячеслав Борисович