Thermo-optic characterization of Yb:CaGdAlO_4 laser crystal

Loiko, Pavel; Druon, Frédéric; Georges, Patrick; Viana, Bruno; Yumashev, K. V.

doi:10.1364/ome.4.002241

Cited by 74 publications

(12 citation statements)

References 25 publications

(35 reference statements)

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“…For the pumped crystal, the following parameters of the thermal lens were used: M 24.9 and 24.1 m −1 ∕W for the mg-and pg-principal meridional planes, respectively [15]. Here, M dD∕d P abs is the so-called sensitivity factor of the thermal lens, P abs is the absorbed pump power, D 1∕f is the optical (refractive) power of the lens, and f is its focal length [28]. Thus, for the maximum studied P abs of 1.9 W, f 21 and 22 mm for the mg-and pg-planes, respectively.…”

Section: Methodsmentioning

confidence: 99%

Passive Q-switching of a Tm,Ho:KLu(WO_4)_2 microchip laser by a Cr:ZnS saturable absorber

et al. 2016

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A diode-pumped Tm;Ho:KLuWO 4 2 microchip laser passively Q-switched with a Cr:ZnS saturable absorber generated an average output power of 131 mW at 2063.6 nm with a slope efficiency of 11% and a Q-switching conversion efficiency of 58%. The pulse characteristics were 14 ns∕9 μJ at a pulse repetition frequency of 14.5 kHz. With higher modulation depth of the saturable absorber, 9 ns∕10.4 μJ∕8.2 kHz pulses were generated at 2061.1 nm, corresponding to a record peak power extracted from a passively Q-switched Tm,Ho laser of 1.15 kW. A theoretical model is presented, predicting the pulse energy and duration. The simulations are in good agreement with the experimental results.

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Section: Methodsmentioning

confidence: 99%

Passive Q-switching of a Tm,Ho:KLu(WO_4)_2 microchip laser by a Cr:ZnS saturable absorber

et al. 2016

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“…The thermal gradient (~50 K between the "hot" and "cold" surfaces, or ~10 K/mm) was applied perpendicularly to the light propagation direction. The experimental details can be found elsewhere [24]. The same sample was used for the determination of thermal expansion coefficient α with a horizontal dilatometer Netzsch 402 PC, providing a precision of ~0.1 × 10 −6 K −1 .…”

Section: Methodsmentioning

confidence: 99%

Thermo-optic properties of Yb:Lu2O3 single crystals

et al. 2015

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Lu 2 O 3 ). Initial growth attempts of sesquioxides utilized the Verneuil method [2,3] or the floating zone technique [4]. The resulting mm-size crystals of low quality were utilized for the initial determination of the optical and thermomechanical properties of these materials and even allowed for first flash-lamp-pumped laser experiments [5]. Afterward, different growth methods such as the laser-heated pedestal growth (LHPG) [6], the micro-pulling down technique [7] and the Czochralski technique [8] were applied, but still the crystals were limited in size and quality. It was not before 2008 that by the optimization of the heat exchanger method [9] the growth of cm-scale single-crystalline sesquioxides with excellent optical quality became possible [10]. In the following years, in particular cubic sesquioxide host material lutetia (Lu 2 O 3 ) has been shown to be an excellent host material for various rare earth ions [11]. Efficient and high-power laser operation has been demonstrated utilizing various laser ions such as Yb 3+ [12,13] at 1 µm, Tm 3+ [14] and Ho 3+ [15] at 2 µm as well as Er 3+ at 3 µm [16].These outstanding laser results obtained in the past motivate a reexamination of the thermo-optic properties of Lu 2 O 3 that affect the parameters of the thermal lens. The lens-like behavior is related with three main effects, namely temperature dependence of the refractive index (expressed by the thermo-optic coefficient, dn/dT), end-bulging related to the thermal expansion coefficient α, as well as photoelastic effect that is responsible for the lens astigmatism and birefringence losses. Under the plane stress approximation (that refers to the diode pumping case), first two terms are dominant [17]. Thus, the knowledge of dn/dT and α values as well as their combination, called thermal coefficient of the optical path (TCOP) [18], is crucial for the determination of the thermal lens parameters and, hence, the cavity design. Indeed, non-compensated thermal lens can lead to Abstract A detailed study of thermo-optic properties of 1.5 at.% Yb:Lu 2 O 3 single crystal is performed. Thermooptic dispersion formulas are derived for dn/dT coefficient and thermal coefficient of the optical path. At the wavelength of 1.03 μm, dn/dT = 5.8 × 10 −6 K −1 . High-precision temperature-dependent measurements of the thermal expansion coefficient α are performed. At the room temperature (RT), α = 5.880 ± 0.014 × 10 −6 K −1 . Temperature dependence of the bandgap is analyzed, yielding RT value of E g = 5.15 eV and dE g /dT = -3.7 × 10 −4 eV/K. Sensitivity factor of the thermal lens is calculated for a diodepumped Yb:Lu 2 O 3 crystal versus the pump spot radius and crystal temperature.

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“…This advantage also contributes to the broadening phenomenon. Additionally, the great thing for Yb: CALGO is that it not only possesses the aforementioned broadening effect, but also shows excellent stability because those two substitute ions (Yb 3+ , 70 and Gd 3+ , 64) have trivial mass difference compared with Yb 3+ (70) and Ca 2+ (20) [37]. The lattice dimensions of Yb:CALGO are usually determined by X-ray diffraction method and the typical results carried out by Talik et al recently are shown in Table 1 [38].…”

Section: Crystal Preparation and Structurementioning

confidence: 99%

Advances of Yb:CALGO Laser Crystals

et al. 2021

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Yb:CaGdAlO4, or Yb:CALGO, a new laser crystal, has been attracting increasing attention recently in a myriad of laser technologies. This crystal features salient thermal, spectroscopic and mechanical properties, which enable highly efficient and safe generation of continuous-wave radiations and ultrafast pulses with ever short durations. More specifically, its remarkable thermal-optic property and its high conversion efficiency allow high-power operation. Its high nonlinear coefficient facilitates study of optimized mode locking lasers. Besides, its ultrabroad and flat-top emission band benefits the generation of complex structured light with outstanding tunability. In this paper, we review the recent advances in the study of Yb:CALGO, covering its physical properties as well as its growing applications in various fields and prospect for future development.

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Thermo-optic characterization of Yb:CaGdAlO_4 laser crystal

Cited by 74 publications

References 25 publications

Passive Q-switching of a Tm,Ho:KLu(WO_4)_2 microchip laser by a Cr:ZnS saturable absorber

Passive Q-switching of a Tm,Ho:KLu(WO_4)_2 microchip laser by a Cr:ZnS saturable absorber

Thermo-optic properties of Yb:Lu2O3 single crystals

Advances of Yb:CALGO Laser Crystals

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