K. Takaichi

72 W Nd:Y3Al5O12 ceramic laser

A high-power continuous-wave polycrystalline 1% Nd:Y{sub 3}Al{sub 5}O{sub 12} (Nd:YAG) ceramic rod laser was demonstrated. With 290 W/808 nm laser diode pumping, cw laser output of 72 W was obtained at 1064 nm. The optical-to-optical conversion efficiency is 24.8%. Thermally induced birefringence properties of Nd:YAG ceramic was also investigated. {copyright} 2001 American Institute of Physics.A high-power continuous-wave polycrystalline 1% Nd:Y3Al5O12 (Nd:YAG) ceramic rod laser was demonstrated. With 290 W/808 nm laser diode pumping, cw laser output of 72 W was obtained at 1064 nm. The optical-to-optical conversion efficiency is 24.8%. Thermally induced birefringence properties of Nd:YAG ceramic was also investigated.

Nd3+:Y2O3 Ceramic Laser

We have demonstrated CW one-micron laser oscillation in new ceramic laser material on the base of cubic Nd3+:Y2O3. Slope efficiency of 32% was achieved on an uncoated 1.5 at.% Nd3+:Y2O3 ceramic plate with size of 14 ×2.7 mm under laser diode end-pumping.

Promising ceramic laser material: Highly transparent Nd3+:Lu2O3 ceramic

A solid-state laser material based on highly transparent cubic Nd3+:Lu2O3 ceramic was developed using nanocrystalline technology and a nonpress vacuum sintering method. Spectroscopic properties of this ceramic laser material were investigated. At room temperature under single-laser diode pumping, efficient continuous wave laser oscillation was demonstrated at two wavelengths of the 4F3/2→4I11/2 channel. The potential application of such a laser material was also discussed.

Yb3+:Y2O3 Ceramics – a Novel Solid-State Laser Material

A new solid-state laser based on Yb3+-doped highly transparent nanocrystalline yttria (Y2O3) ceramics was developed. At room temperature and under a pump power of 2.63 W from a single InGaAs laser diode at ≈ 0.94 µm, a continuous-wave laser output of 0.47 W at 1.077 µm wavelength was obtained corresponding to a slope efficiency of about 32%. Some main spectroscopic properties of Yb3+:Y2O3 ceramics were also investigated.

Microhardness and fracture toughness of Y2O3-and Y3Al5O12-based nanocrystalline laser ceramics

The microhardness and fracture toughness of laser nanocrystalline ceramics based on the cubic oxides Y2O3 and Y3Al5O12 are determined experimentally. It is shown by comparative measurements that the fracture toughness and microhardness of Y2O3 ceramics exceed the corresponding parameters of Y2O3 single crystals by factors of 2.5 and 1.3, respectively. The fine morphology of grains and grain boundaries in fractures is investigated. It is ascertained that changes in the mechanical properties of the nanocrystalline ceramics under study are related to both the sizes and structure of grains and the structure of grain boundaries. It is suggested that twinning processes determine the mechanisms of formation of nanocrystalline ceramics.

Highly efficient continuous-wave operation at 1030 and 1075 nm wavelengths of LD-pumped Yb3+:Y2O3 ceramic lasers

Room-temperature cw laser oscillations at 1030 and 1075 nm wavelengths were demonstrated for the TEM00 mode with Yb3+:Y2O3 ceramics by LD-pumping. A maximum extraction efficiency of 72% at 1075 nm lasing wavelengths and of 45% at 1030 nm lasing wavelengths were observed.

Yb3+:Sc2O3 ceramic laser

A solid-state laser material based on highly transparent Yb3+-doped scandia (Sc2O3) ceramic was developed using nanocrystalline technology and the nonpress vacuum sintering method. Continuous wave laser oscillations were obtained at around 1041 and 1094 nm using a 2.5 at. % Yb3+:Sc2O3 ceramic plate. Broadband lasing spectra were observed.

36-W diode-pumped continuous-wave 1319-nm Nd:YAG ceramic laser

Continuous-wave output at 1319 nm was obtained from a laser-diode-pumped 1% ceramic Nd:YAG laser. As much as 36.3-W output was obtained under pump power of 290 W, with an optical-to-optical conversion efficiency of 12.5%.

Monoclinic bismuth triborate BiB3O6 – a new efficient χ(2)+χ(3)-nonlinear crystal: multiple stimulated Raman scattering and self-sum-frequency lasing effects

Abstract Efficient multiple stimulated Raman scattering (SRS) and other χ (3) and χ (2) nonlinear effects in monoclinic BiB 3 O 6 crystal were observed under picosecond excitation. The majority of measured Raman laser wavelengths in the near-IR and visible are identified and attributed to the SRS-active vibration modes of bismuth triborate. We classify the BiB 3 O 6 acentric compound as promising media for Raman laser converters.

New data on the physical properties of Y3Al5O12-based nanocrystalline laser ceramics

Microhardness and fracture toughness of highly transparent Y3Al5O12-and Y3Al5O12: Nd3+-based nanocrystalline ceramics are measured for the first time. For the Y3Al5O12: Nd3+ laser ceramics, the use of a longitudinal scheme with a diode-laser pumping at a wavelength of 1.3186 mm (4F3/2 → 4I13/2 channel) enabled one to attain an output power of continuous-wave lasing of ∼3.7 W with 35% efficiency.