Random laser action in stoichiometric Nd3Ga5O12garnet crystal powder

Iparraguirre, I.; Azkargorta, J.; Kamada, Kei; Yoshikawa, Akira; Rodrı́guez-Mendoza, U.R.; Lavı́n, V.; Barredo-Zuriarrain, Macarena; Balda, Rolindes; Fernández, J.

doi:10.1088/1612-2011/13/3/035402

Cited by 12 publications

(10 citation statements)

References 16 publications

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“…We have observed that, in Nd stoichiometric crystal powders with a similar grain size, this delay time is much shorter [34,35]. In regular laser systems, this delay time between pump intensity and emission fluctuations is determined by the residence time of the photon inside the resonator [36].…”

Section: Resultsmentioning

confidence: 99%

“…The slope efficiency in the Nd:YAG crystal powder is lower than those of Nd in stoichiometric crystal powders with a similar grain size, which can achieve a value close to a 40% due to their higher absorbance peaks [33,35]. It is important to remark that this value of the slope efficiency means that every absorbed photon above the threshold energy is reemitted again as a stimulated emission photon.…”

Section: Resultsmentioning

confidence: 99%

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Random Laser Action in Nd:YAG Crystal Powder

et al. 2016

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This work explores the room temperature random stimulated emission at 1.064 μm of a Nd:YAG crystal powder (Neodymium-doped yttrium aluminum garnet) in a very simple pump configuration with no assistance from an internal mirror. The laser threshold energy as a function of pump beam area and pump wavelength has been measured, as well as the temporal dynamics of emission pulses. The absolute energy of stimulated emission and the absolute laser slope efficiency have been measured by using a method proposed by the authors. The results show a surprising high efficiency that takes the low Nd3+ ion concentration of the crystal powder into account.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Random Laser Action in Nd:YAG Crystal Powder

et al. 2016

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“…Using a fiber‐coupled random laser, where the pump fiber terminates deep inside the scattering medium in order to deliver the pump energy directly into the gain volume without reflection loss at the surface, Noginov et al achieved a higher efficiency of ≈0.7% . Azkargorta et al achieved 20% and 42% slope efficiencies with respect to pump power using Nd: yttrium aluminium garnet (YAG) and Nd 3 Ga 5 O 12 crystal powders …”

Section: Introductionmentioning

confidence: 99%

Polydispersed Powders (Nd³⁺:YVO₄) for Ultra Efficient Random Lasers

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Giehl

Butzbach

et al. 2017

Part & Part Syst Charact

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inherent cost advantages become attractive for the large majority of applications.In order to overcome the problems of random lasers associated to nondirectional output and lack of efficiency, the main approach has been to choose lowdimensional random lasers. 1D fiber random lasers are well suited for this purpose and have achieved up to several watts of continuous output. [10] 2D distributed feedback (DFB) lasers have demonstrated highly efficient and directional output in the microjoule range. [11] These low-dimensional random lasers are generally quite large (like in the case of random fiber lasers) and require sophisticated production methods that are in stark contrast to the simplicity and practicality of the 3D random laser production.Noginov and co-workers have studied the dependence of random laser emission in neodymium doped powders (Nd 0.5 La 0.5 Al 3 (BO 3 ) 4 ) on the particle size, the powder volume density, and the pump spot size. [12,13] Best reported efficiency was below half a percent. An impediment for increasing the efficiency is the surface reflectivity of the compacted powders. The bulk reflection coefficient of Nd 0.5 La 0.5 Al 3 (BO 3 ) 4 at λ = 532 nm for medium to high powder density is ≈0.7. [13] Using a fiber-coupled random laser, where the pump fiber terminates deep inside the scattering medium in order to deliver the pump energy directly into the gain volume without reflection loss at the surface, Noginov et al. achieved a higher efficiency of ≈0.7%. [14] Azkargorta et al. achieved 20% and 42% slope efficiencies with respect to pump power using Nd: yttrium aluminium garnet (YAG) and Nd 3 Ga 5 O 12 crystal powders. [15,16] The stimulated random laser (RL) emission of these rare earth doped powder pellets comes in the form of a Lambertian emission with a linewidth that decreases around laser threshold and becomes much smaller than typical amplified spontaneous emission (ASE). [17] Output power also shows a typical laser threshold and slope efficiency. As we have shown for yttrium vanadate doped with neodymium (Nd:YVO 4 ), the emission decay after a pump pulse follows two different exponentials corresponding to a fast laser emission decay of a few microseconds and a slower fluorescence emission decay which is shorter than the intrinsic decay time, which should amount to 73 µs for 1.33 mol% neodymium doping concentration, because of upconversion. [18] We therefore expected some decrease in laser efficiency due to energy transfer upconversion.Random lasers hold the potential for cheap, coherent light sources that can be miniaturized and molded into any shape with several other added benefits such as speckle-free imaging; however, they require improvements specifically in terms of efficiency. This paper details for the first time a strategy for increasing the efficiency of a random laser that consists in using smaller particles, trapped between large particles to serve as absorption and gain centers whereas the large particles control mainly the light diffusion into the sample. Measurements...

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“…As the RL experiments show [12,29,32,33], far enough above threshold, the output/input energy function asymptotically tends to a line of slope one. As can be seen in Fig.…”

Section: Results From the Numerical Model In The Energy Domainmentioning

confidence: 94%

“…In Fig. 4 we show the experimental energy output/input of a Neodymium Gallate [29,32,33] together with the results of our simulation using different values of p and σ. The optimal fit is obtained for values of p slightly lower than 0.1 and the stimulated emission cross-section is not very sensitive to changes in p. Figure 5 shows the theoretical fitting for a Neodymium Borate [29,32,34].…”

Section: Results From the Numerical Model In The Energy Domainmentioning

confidence: 99%

Random laser model for Nd³⁺-doped powders and its application to stimulated emission cross-section calculations

et al. 2018

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A new theoretical approach for random lasing of Nd 3+ doped powders is presented. The model's singularity lies in the fact that it proposes a probability distribution of the stimulated photon paths lengths in the sample, as well as a population inversion shared by different photon paths. The model's predictions satisfactorily compare with the results of laser threshold and absolute input/output energy slope of a real Random Laser. The main novel issue is that the best fit to the experimental results requires considering a high level of shared population inversion among different paths. The model simulation of local and spatially integrated Random Laser emissions, as well as their time evolution, is in accordance with the experimental behavior. These results also provide a new method of measuring the stimulated emission cross-section in this kind of random laser materials.

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Random laser action in stoichiometric Nd₃Ga₅O₁₂garnet crystal powder

Cited by 12 publications

References 16 publications

Random Laser Action in Nd:YAG Crystal Powder

Random Laser Action in Nd:YAG Crystal Powder

Polydispersed Powders (Nd³⁺:YVO₄) for Ultra Efficient Random Lasers

Random laser model for Nd³⁺-doped powders and its application to stimulated emission cross-section calculations

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Random laser action in stoichiometric Nd3Ga5O12garnet crystal powder

Cited by 12 publications

References 16 publications

Random Laser Action in Nd:YAG Crystal Powder

Random Laser Action in Nd:YAG Crystal Powder

Polydispersed Powders (Nd3+:YVO4) for Ultra Efficient Random Lasers

Random laser model for Nd3+-doped powders and its application to stimulated emission cross-section calculations

Contact Info

Product

Resources

About

Random laser action in stoichiometric Nd₃Ga₅O₁₂garnet crystal powder

Polydispersed Powders (Nd³⁺:YVO₄) for Ultra Efficient Random Lasers

Random laser model for Nd³⁺-doped powders and its application to stimulated emission cross-section calculations