<title>Passive Q-switches for diode-pumped laser resonators</title>

Abstract

The paper presents the results of investigations on spectroscopic properties of new non-linear absorbers used for diodepumped laser systems: yttrium-aluminium garnet doped with trivalent vanadium ions (YAG:V3) and Te doped GaAs semiconductor absorber.In this work we present the results on YAG:V3 single crystal growth and examination of Q-switching of laser resonator in near JR band. YAG single crystals doped with V3 ions of different concentrations were obtained by the Czochralski method. The absorption and emission spectra measurements on those crystals are presented. The as grown crystals have not non-linear absorption bands of V3 ions in tetrahedral positions (820 nm, 1100 nm and 1300 nm). After crystals annealing in reducing atmosphere absorption bands in NIR region arise. The investigations of changes in transmission properties of YAG crystals with different concentrations of V3 ions have been carried out as a function of power density of transmitted radiation at 822 nm (Ti:Sapphire laser), 1064 nm, and 13 18 nm (YAG:Nd3 laser). Dependence of transmission changes of the GaAs:Te on power density of diagnostic radiation of 1064 nm have been determined. The following parameters of non-linear absorbers were estimated: non-active losses, absorption cross-section, saturation energy, concentration of active centres, relaxation time, and energy losses caused by absorber bleaching.Generation characteristics ofYAG:Nd3 laser with GaAs:Te and YAG:V3 modulators have been investigated.

Electronic Structure of Y3Al5O12:V Single Crystals, Comparison with Sintered Ceramics

“…A wafer from a middle part of the crystals was used for examinations. The wafer of YAG:0.8at.%V was divided into four parts, which were annealed in reduction atmospheres: (1) in hydrogen, at 1200…”

“…Such materials are especially attractive for Q-switching operation to obtain high peak power optical pulses [1]. Recently the YAG ceramics were synthesized to replace the YAG single crystals.…”

Saturable absorbers based on tetrahedrally coordinated transition-metal ions in crystals (Review)

“…It must be noted that TC V The time for restoration of the initial absorption of V 3+ :Y 3 Al 5 O 12 crystal is, according to various reports, 5 [113], 22 [114], or 37 nsec [14] and characterizes the time for radiationless relaxation from lower excited state (Fig. 14b) and are located in the ranges λ ≈ 0.87 and ≈0.74 μm.…”

Nd:YAG/V:YAG microchip laser operating at 1338 nm

“…From this reason using of the Cr:YAG crystal as the passive Q-switch limits the operating wavelength of the Nd 3+ ions in the range around 1 µm, and it is not suitable for longer wavelength transitions, such as 1.3 µm transitions of Nd 3+ ions. As a reliable Q-switch for the 1.3 µm spectral region, a solid state crystal V:YAG (Yttrium-Aluminum Garnet doped with three-valence vanadium V 3+ ) is possible to use, because V 3+ ions absorbs radiation in the range from 0.9 to 1.5 µm [5][6][7]. This saturable absorber was studied in many arrangements together with different Nd 3+ ions doped hosts [8][9][10][11].…”