Yoichi Sato

RIKEN | RIKEN AICS · SPring-8 Center (RSC)

The linear thermal expansion coefficients of Nd:YAG single crystals and YAG ceramics doped with Nd ³⁺ , Yb ³⁺ , Er ³⁺ , Sm ³⁺ , and Cr ⁴⁺ ions were evaluated. We experimentally detected no significant differences larger than measurement errors.

We evaluated the linear thermal expansion coefficient (α) of various laser host crystals with cubic symmetry by first principles calculations, where the relation of calculated α was CaF2 >> Sc2O3 > ZnS > ZnSe ∼ Lu3Al5O12 > Y3Al5O12 > Y2O3 > Lu2O3 at 300 K. The variation of temperature dependent α for these materials in past reports are approximatel...

Thermal conductivity, thermal expansion, and temperature coefficient of refractive index of YAG single crystal were comprehensively studied under the wide temperature range from cryogenic region to the high temperature, which covers whole laser operation condition.

We measured the isopiestic specific heat (CP) of Y3Al5O12 (YAG) by the differential scanning calorimetry aiming to obtain thermal parameters under cryogenic and room-temperature (RT) conditions. It was also found that the applicable temperature range of our numerical model for CP of YAG was updated to the range between 129 K and 573 K with below 3%...

We proposed numerical models for thermal expansion of ceramic laser materials from 150K to 900K, where expansion was CaF 2 >> Sc 2 O 3 > ZnS > ZnSe ~ Lu 3 Al 5 O 12 > Y 3 Al 5 O 12 > Y 2 O 3 > Lu 2 O 3 at 300K.

The specific heat (CP) of Y3Al5O12 from -150 °C to 300 °C was evaluated. We can extend the applicable temperature range of our numerical model of CP for Y3Al5O12 to cryogenic region of 200 K.

To expand the possibility of laser ceramics, we proposed the magnetic orientation control of microdomains in polycrystalline ceramics made of non-isometric crystals. Here the design of the extensive variables in Gibbs energy by inducing 4 f electrons of the rare-earth trivalent into the controlled microdomains enhanced the motive forces and torques...

Using polycrystalline Yb3+-doped fluoroapatite (Yb:FAP), we investigated quantum mechanics for orientation-control of microdomains in anisotropic laser ceramics with 4f-electrons of RE3+-ion. Kilowatt-level sub-ns laser pulses were generated with the extraction density of 0.34 J/cm3.

By energy dispersive x-ray spectroscopy we identified the source of the secondary phase in Yb:FAP ceramics that limit the lasing volume. We also found that the reduction of Yb3+-concentration drastically reduced this secondary phase.

The power scaling of laser devices can contribute to the future of humanity. Giant microphotonics have been advocated as a solution to this issue. Among various technologies in giant microphotonics, process control of microdomains with quantum mechanical calculations is expected to increase the optical power extracted per unit volume in gain media....

Polarization dependence of saturable absorption in Cr⁴⁺:YAG was investigated. We theoretically proposed its general analytical formula expressed in terms of the intensity and the polarization angle of the pump beam. We also derive transmission formulas for specific incident surfaces of (100)-, (110)-, and (111)-planes. In order to prove our model,...

We theoretically proposed the practical notation for the saturable absorption in Cr4+:YAG in terms of the polarization angle. This model was examined by use of (110)-cut Cr4+:YAG with the initial transmittance of 75%.

The saturable absorption in the Cr4+:YAG ceramics was investigated for designing efficient Q-switched lasers. We confirmed that Cr4+:YAG ceramics perform the saturable absorption similarly to Cr4+:YAG single crystal for [110]-polarized pump sources.

Thermal parameters of optical materials, such as thermal conductivity, thermal expansion, temperature coefficient of refractive index play a decisive role for the thermal design inside laser cavities. Therefore, numerical value of them with temperature dependence is quite important in order to develop the high intense laser oscillator in which opti...

Authors investigated the variation of the spiking interval during the start of the relaxation oscillation at the zero-phonon line in Yb-gain media, and proposed a novel procedure for evaluating effective spectroscopic parameters of gain media.

Polarization dependence of saturable absorption in Cr4+:YAG was investigated. We theoretically proposed and experimentally proved its notation given by the function of the angle θ between representative axes of incident surfaces and the polarization.

We have realized highly transparent Yb:fluorapatite (FAP) ceramics by use of slip casting under rotational magnetic field, even though the main crystal axis become a hard magnetization axis due to the enhancement of magnetic anisotropy by the total angular momentum of 4f electrons in doped rare-earth ions. We confirmed that our Yb:FAP ceramics reac...

Experimental errors in the interferometric evaluation for temperature coefficient of refractive index (dn/dT) were studied. We updated dn/dT of Nd:vanadates with the reduction of experimental errors from 7.8% to 1.5% compared to our previous report.

Thermo-mechanical and -optical properties of Y3Al5O12 (YAG), YVO4, and GdVO4 were evaluated with less than 2% of evaluation error. Measured thermal expansion coefficient for YAG, [100]-YVO4, [001]-YVO4, [001]-GdVO4, and [001]-GdVO4 were 6.13, 1.76, 8.24, 1.19, and 7.26 × 10⁻⁶/K at room temperature. Temperature coefficients of refractive index for Y...

Thermo-mechanical and -optical properties of YAG, YVO₄, and GdVO₄ were accurately evaluated and tabulated. It was also revealed that thermal expansion of YAG is independent on the crystal orientation against conventional knowledge.

Yb doped FAP ceramics obtained under rotating magnetic field is optically characterized revealing the laser grade of the material. We obtain 0.8cm-1 for cavity loss coefficient.

We present theoretical studies on the orientation control of micro-domains in anisotropic laser ceramics. The direction of the crystal axis that is parallel to easy magnetization in each micro-domain can be aligned along the direction of the applied magnetic field via two steps of fabrication processes. In the first step the alignment is performed...

We present theoretical studies on the orientation control of micro-domains in anisotropic laser ceramics, and produce the distribution function of the crystal orientation in micro-domains including anisotropic laser ceramics. Also the improvement in the orientation distribution caused by preferential grain growth is discussed, where our theoretical...

Reduction of absorption coefficient due to heat-up in hot-band pumped Nd:YAG was studied, and it was much smaller than cold-band pumping. In addition, the necessity of correction in the traditional model for line-bandwidth became clear.

Temperature dependencies of stimulated emission cross section for Nd:YAG, Nd:YVO4, and Nd:GdVO4 was carefully evaluated. Our spectral evaluations with fine spectral resolution were carried out under the condition that the population inversion was induced into samples by a weak pumping field. Within the temperature range from 15°C to 65°C, the varia...

We propose the experimentally proved numerical model for temperature dependence of stimulated emission cross section, where Nd:YAG, Nd:YVO4, and Nd:GdVO4 show -0.20%/degC, -0.50%/degC, and -0.48%/degC at 1.06 μm under room temperature, respectively.

Principles that enable to synthesize anisotropic laser ceramics have been established. Anisotropic laser ceramics contain micro domains made of anisotropic crystals, and we have invented the novel alignment technology of micro domain structure in laser ceramics assisted by rare-earth trivalent. Our novel process is essentially superior to the tradi...

Numerical model for temperature dependent cross section of Nd-doped materials is proposed. Variation of cross section in Nd:YAG is -0.20%/°C, which is 40% and 54% of Nd:orthovanadates in π- and σ-polarization, respectively.

It was found that the temperature dependence of stimulated emission cross section (σem) of Nd:YVO4 and Nd:GdVO4 were severer than Nd:YAG. σem of Nd:YAG, Nd:YVO4, and Nd:GdVO4 decreased 0.20%/degC, 0.50%/degC, and 0.48%/degC at 20degC, respectively.

It was experimentally found that electronic structures of Russell-Saunders manifolds in Nd:YAG depended on the Nd³⁺-doping concentration (C Nd) and its fabrication process. Both of the bandwidth and the branching ratio in fluorescent transitions in Nd:YAG varied almost linearly depending on C Nd, and a fabrication process has its own diluted limit...

Laser action of the photo-thermo-refractive (PTR) glass, which is the photosensitive material for holographic recording of volume Bragg gratings (VBGs), was demonstrated for the first time by introducing Nd 3 + . Nd:PTR glass has a bandwidth of 27.8 nm and 16.0 nm for luminescence and absorption, respectively. An uncoated 2 mm thick Nd:PTR element...

We found 30.9% difference in stimulated emission cross section at 1319 nm between 0.4at.% and 5.4at.% Nd:YAG ceramics by fine spectroscopy. It was also revealed that Stark splitting of Nd:YAG depended on Nd3+-concentration and fabrication processes.

We report the first demonstration of a diode-pumped anisotropic ceramic laser that uses microdomain-controlled neodymium-doped hexagonal fluorapatite [Nd3þ:Ca10(PO4)6F2, Nd:FAP] polycrystalline ceramics as the gain medium, which were fabricated by the rare-earth-assisted magnetic grain-orientation control method, as a step toward achieving giant mi...

Export Date: 31 July 2012, Source: Scopus, CODEN: OPLED, doi: 10.1364/OL.36.002257, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Taira, T., (2007) IEEE J....

Conference code: 86146, Export Date: 31 July 2012, Source: Scopus, Art. No.: 5950296, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Kaminskii, A.A., Sh. Akc...

Cited By (since 1996): 6, Export Date: 31 July 2012, Source: Scopus, Art. No.: 022703, doi: 10.1143/APEX.4.022703, Language of Original Document: English, Correspondence Address: Akiyama, J.; Laser Research Center for Molecular Science, Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan; email: akiyama@ims.ac.jp, References: Ikesue, A....

The fabrication of laser-grade anisotropic ceramics by a conventional sintering process is not possible owing to optical scattering at randomly oriented grain boundaries. In this Letter, we report the first (to our knowledge) realization of transparent anisotropic ceramics by using a new crystal orientation process based on large magnetic anisotrop...

Conference code: 81787, Export Date: 31 July 2012, Source: Scopus, Art. No.: 5500392, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Vorobiev, N., Single-fre...

Laser oscillation of Nd3+-doped photo-thermo-refractive glass (Nd:PTR) were examined for the first time. We confirmed that laser efficiency of Nd:PTR is stable even with wavelength shift of pump source due to its wide absorption bandwidth.

The practicable model on thermal conductivity of laser materials for numerical heat design in laser cavities is proposed. By a few parameters, this model can express temperature dependence of thermal conductivity with any rare-earth concentration.

Conference code: 78301, Export Date: 31 July 2012, Source: Scopus, Art. No.: 5194727, doi: 10.1109/CLEOE-EQEC.2009.5194727, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan, References: Vorobiev, N., Single-frequency-mo...

In this research, a new method of "advanced electromagnetic processing" has been established for fabricating transparent rare-earth doped anisotropic ceramics toward the Giant Micro Photonics. We applied it for RE:FAP (RE:Ca10(PO4)6F2) materials that have excellent optical properties such as high absorption efficiency, high emission cross-section a...

We have proposed a new model of thermal conductivity, which is applicable for both single-crystalline and poly-crystalline Y3Al5O12. This model can explain the temperature dependence of thermal conductivity from room temperature to 200 degrees C. By comparing the measured value of thermal conductivity in Nd3+ and Yb3+-doped Y3Al5O12, we can involve...

Transparent anisotropic ceramics with oriented grain structure have been developed by means of advanced electromagnetic processing. We report the first demonstration of RE: FAP (RE: Nd, Yb) ceramics, which have laser-grade transparency.

We have confirmed that there is severe dependence of fluorescent profiles in Nd:Y3Al5O12ceramics on Nd3+-doping concentration. Especially at 1319-nm stimulated emission cross section becomes -46% by 8.9at.% Nd3+-doping compared to 1.0at.% samples.

Conference code: 78099, Export Date: 31 July 2012, Source: Scopus, Art. No.: 5224485, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Taira, T., RE3+-ion-dope...

The spectroscopic properties of Nd3+-doped photo-thermo-refractive glass (Nd:PTR) were evaluated for the first time. Authors assures that Nd:PTR is the promised laser medium due to optical qualities and designability of Nd:PTR.

We have proposed a novel model of thermal conductivity in various optical materials. This numerical model for thermal conductivity requires one material parameter for isovolumic specific heat and two parameters for thermal diffusivity in the calculation of each optical material. The validity of our model was demonstrated and it was adequately able...

Conference code: 73401, Export Date: 31 July 2012, Source: Scopus, Art. No.: 4551758, doi: 10.1109/CLEO.2008.4551758, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, Refe...

Characterization of thermal conductivity with temperature dependence is much important for designing of the high power lasers. A simple model of thermal conductivity for various optical materials, such as Y3Al5O12, YVO4, GdVO4, stoichiometric and congruent LiTaO3, and synthetic quartz, has been established: one parameter for specific heat and two p...

9.6-W cw green output power with package volume of 150-cm3 was obtained. In order to downsize a system, we have applied an edge-pumping concept for an intra cavity frequency doubled vanadate microchip laser.

In this work we summarized thermal characteristics of YVO₄ with comparative study of GdVO₄ by using of carefully evaluated kappa, alpha, dn/dT, thermal heat capacity coefficient dC_p/dT, and thermal conductivity coefficient dkappa/dT. In conclusion, we summarized thermo-mechanical and -optical parameters of GdVO<sub>...

Highly transparent Nd3+-doped Y3ScAl4O12 (YSAG) ceramics with up to 5.0 at.% Nd3+-concentration (CNd) were synthesized from commercial oxide powders with purity of >99.99% by a solid-state reaction method. Absorption, fluorescence, and decay properties of these materials were evaluated. Considering the influence of increasing CNd on these spectrosc...

A passively mode-locked femtosecond Yb3+-doped Y3(Sc0.5Al0.5)2O12 (Yb:YSAG) ceramic laser has been studied. The new material, fabricated by sintering method, exhibited relatively low minimum pump intensity (Imin) and broad emission bandwidth even in the yttrium aluminum garnet systems. The value of Imin in the Yb:YSAG ceramics was found to be 2/3 c...

We measured thermal conductivity, thermal expansion coefficient, and thermal refractive index coefficient of Nd:GdVO₄ and Nd:YVO₄. Superiority comparisons of laser media under high power laser operations were also discussed from the viewpoints of thermal characteristics.

Composite structures in GdVO₄ single crystals were directly grown by double die EFG method, which enables 3-mm core of Nd:GdVO₄ inside 5-mm clad of pure GdVO₄. Laser oscillation of our composite was successfully demonstrated.

We have proposed an optical design by tailoring a spectral profile in a ceramic composite of layer-by-layer type Nd:Y₃Al₅O₁₂/Nd:Y₃ScAl₄O₁₂. The composite ceramics with enough optical properties to amplify the stimulated emission were fabricated by the sintering method with solid stat...

Core-clad-type composite structures in GdVO4 single crystals were directly fabricated by single-crystal-growth techniques. The double die EFG method enables 3-mm core of Nd:GdVO4 inside 5-mm clad. Laser oscillation in our samples was successfully demonstrated.

High-power Nd:GdVO4 microchip laser with a single-pass green generation in PPMgLN has been developed. Quasi-cw 27.3-W fundamental output generated 8.8-W green power with conversion efficiency of 34% from the PPMgLN device of 1-mm thickness.

We have evaluated thermal conductivities (κ) in polycrystalline Nd3+- and Yb3+-doped YAG ceramics. The differences of κ of YAG between two types of ceramics and single crystals that have various RE3+-concentrations were also discussed.

Conference code: 87568, Export Date: 31 July 2012, Source: Scopus, Art. No.: 4452338, doi: 10.1109/CLEO.2007.4452338, Language of Original Document: English, Correspondence Address: Matsukura, M.; Oxide Corporation, Mukawa, Hokuto, Yamanashi 408-0302, Japan; email: matsukura@opt-oxide.com, References: Asakawa, Y., Kawai, R., Ohki, K., Otsuka, K., L...

Cited By (since 1996): 2, Export Date: 31 July 2012, Source: Scopus, CODEN: IJSQE, doi: 10.1109/JSTQE.2007.896564, Language of Original Document: English, Correspondence Address: Sato, Y.; Institute for Molecular Science, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Ikesue, A., Aung, Y.L., Tkira, T., Kamimura, T., Yoshida, K., Prog...

We have proposed an optical design by tailoring a spectral profile in a ceramic composite of layer-by-layer type Nd:Y3Al5O12/Nd:Y3ScAl4O12. The composite ceramics with enough optical properties to amplify the stimulated emission were fabricated by the sintering method with solid state reaction. After the investigation of spectroscopic property, the...

We have measured thermal conductivity of GdVO4, YVO4, and Y3Al5O12. In order to avoid the miss leading from three-dimensional (3D) thermal diffusion, we developed the quasi-one-dimensional (q1D) flash method. By taking in account the heat radiation effect in transparent materials for this measurement, YVO4 was found to have larger thermal conductiv...

We have evaluated the thermal conductivity ( κ ) in polycrystalline YAG ceramics and crystalline YAG single crystals. The influence of Nd-doping on κ was discussed, and found a dependence of κ on fabrication methods.

We have measured thermal conductivity of Y3Al5O12, GdVO4, and YVO4. It was found that YVO4 has larger thermal conductivity than GdVO4. Nd3+-doping effect in thermal conductivity and thermal expansion ratio have been also discussed.

There has been considerable interest in the trivalent rare earth-ion-doped ceramic laser materials because of its numerous advantages over melt growth methods, including faster production times, solid solution allowing the fabrication of multi-phase transition materials, highly homogeneous materials and the ability to engineer profiles and structur...

We have demonstrated laser oscillation in a ceramic layered composite Nd:Y3Al5O12/Nd:Y3ScAl4O12. The slope efficiency was 39% even if uncoted material. After the investigation of spectroscopic property, the possibility of tailored fluorescence spectral profile was discussed.

Cited By (since 1996): 47, Export Date: 31 July 2012, Source: Scopus, doi: 10.1364/OE.14.010528, Language of Original Document: English, Correspondence Address: Sato, Y.; Institute for Molecular Science, 38 Nishigonaka, Myodaiji-machi, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Tsunekane, M., Taira, T., High-power operation of di...

In this work, we fabricated the all-ceramic composite with layer-by-layer of Nd:Y₃ScAl₄O₁₂ (YSAG) and Nd:Y₃Al₅O₁₂ (YAG). We found that the tuning of the pumping wavelength made the spectral profile of fluorescence from the composite ceramics more even than that from single-layered Nd...

Conference code: 65869, Export Date: 31 July 2012, Source: Scopus, Art. No.: JTuC28, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Walsh, B.M., Compositiona...

We demonstrated a near quantum-limited slope efficiency in 1.3-μm cw Nd:GdVO₄ laser under a 879-nm (Ti:Sapphire laser) pumping. Large heat generation due to non-radiative decay in Nd:GdVO₄ crystal under non-lasing condition was discussed.

We have proposed a hybrid procedure for determining spectroscopic parameters for uniaxial solid-state laser crystals. Using our procedure, the spectroscopic properties of Nd:GdVO₄ were evaluated and compared to those of Nd:YVO₄. As a result, the peaks of absorption and stimulated emission cross sections of Nd:GdVO₄...

We demonstrated a near quantum-limited slope efficiency in 1.3-µm cw Nd:GdVO4 laser under a 879-nm (Ti:Sapphire laser) pumping. Large heat generation due to non-radiative decay in Nd:GdVO4 crystal under non-lasing condition was discussed.

Conference code: 66935, Export Date: 31 July 2012, Source: Scopus, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Taira, T., Modeling of quasi-three-level la...

We report on a highly efficient (over 60% slope efficiency) 1.3-µm cw Nd:GdVO4 laser pumped by a 879-nm Ti:Sapphire laser. Non-radiative transition induced heat generation in Nd:GdVO4 crystal under lasing and non-lasing conditions are discussed.

We have investigated spectroscopic properties of Yb:GdVO4, and their Stark sub-levels and selection rules were discussed. The precise spectroscopic parameters were also obtained, 6.1 and 6.7x10-20-cm2 as absorption and emission cross-sections at 984-nm, respectively.

We have proposed a hybrid procedure for determining spectroscopic parameters for uniaxial solid-state laser crystals. Using our procedure, the spectroscopic properties of Nd:GdVO4 were evaluated and compared to those of Nd:YVO4. As a result, the peaks of absorption and stimulated emission cross sections of Nd:GdVO4 in pi-polarization were determine...

Conference code: 69012, Export Date: 31 July 2012, Source: Scopus, Art. No.: 1567854, CODEN: 85PNA, doi: 10.1109/CLEOE.2005.1567854, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan, References: A....

Conference code: 66935, Cited By (since 1996): 13, Export Date: 31 July 2012, Source: Scopus, Language of Original Document: English, Correspondence Address: Saikawa, J.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan, References: Lupei, V., Pavel, N., Sato, Y., Taira,...

Conference code: 66394, Export Date: 31 July 2012, Source: Scopus, Art. No.: CMS6, Language of Original Document: English, Correspondence Address: Saikawa, J.; Laser Research Center for Molecular Science, Institute for Molecular Science, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan, References: Lupei, V., Pavel, N., Sato, Y., Taira, T., Highly...

The continuous-wave high power laser emission of Nd:GdVO4 at the fundamental wavelength of 1.06 mm and its 531-μm second-harmonic obtained by intracavity frequency-doubling with a LBO nonlinear crystal is investigated under pumping by diode laser on the 4I9/2 → 4 F5/2 transition, at 808 nm, and on the 4I9/2 → 4F3/2 transition, at 879 nm. 5.1 W at 5...

Cited By (since 1996): 46, Export Date: 31 July 2012, Source: Scopus, CODEN: IJSQE, doi: 10.1109/JSTQE.2005.850569, Language of Original Document: English, Correspondence Address: Sato, Y.; Laser Research Center, Institute for Molecular Science, Okazaki 444-8585, Japan; email: yoichi@ims.ac.jp, References: Sato, Y., Taira, T., Spectroscopic propert...

We demonstrated a near quantum-limited slope efficiency in 1.3-mum cw Nd:GdVO4 laser under a 879-nm (Ti:Sapphire laser) pumping. Large heat generation due to non-radiative decay in Nd:GdVO4 crystal under non-lasing condition was discussed

Spectroscopic properties in Nd:GdVO4were studied. In order to estimate the radiative quantum efficiency, authors proposed the Hybrid Process. Estimated radiative quantum efficiency of 1.0-at.% Nd:GdVO4was found to be smaller than for 1.0-at.% Nd:YVO4.

We have demonstrated a passively mode-locked Yb3+-doped Y3ScAl4O12 ceramic laser, which is a solid solution of Y3Al5O12 and Y3Sc2Al3O12, by using a semiconductor saturable-absorber mirror. The maximum average output power was as high as 150 mW with a pulse duration of 500 fs. With a 0.5% output coupler, pulses as short as 280 fs having an average o...

Conference code: 64543, Cited By (since 1996): 2, Export Date: 31 July 2012, Source: Scopus, Art. No.: 24, CODEN: PSISD, doi: 10.1117/12.582810, Language of Original Document: English, Correspondence Address: Lupei, V.; Institute of Atomic Physics-INFLPR, Solid-State Quant. Electron. Lab., 76900 Bucharest, Romania, References: Geller, S., Espinosa,...

Conference code: 64543, Cited By (since 1996): 1, Export Date: 31 July 2012, Source: Scopus, Art. No.: 14, CODEN: PSISD, doi: 10.1117/12.582790, Language of Original Document: English, Correspondence Address: Pavel, N.; Institute for Molecular Science, Laser Research Center, 38 Nishigonaka, Okazaki 444-8585, Japan; email: npavel@ims.ac.jp, Referenc...

We report on the continuous-wave laser performances of Yb ³⁺ -doped disordered Y ₃ Al ₅ O ₁₂/ Y ₃ Sc ₂ Al ₄ O ₁₂ ( YAG / YSAG ) ceramics fabricated by sintering method. These materials exhibit relatively low minimum pump intensity (I_min) and broad e...

The 80.3% of slope efficiency has been achieved in 1-μm cw laser oscillation by Nd:GdVO4: this is the highest efficiency in Nd3+ lasers. Spectroscopic properties of Nd:GdVO4 compared to those of Nd:YVO4 were also discussed.

Transparent Nd3+-doped Y3ScAl4O12 (Nd:Y3ScAl4O12) ceramics with up to 5.0-at.% Nd33+-concentration (CNd) were fabricated by a solid-state reaction method using commercial 4N powders. Spectroscopic properties of this media, such as absorption and emission spectra, the fluorescence lifetime, and the influence of increasing CNd on these characteristic...