Continuous-wave and Q-switched microchip laser performance of Yb : Y3Sc2Al3O12 crystals

Optical properties of Yb:Y3Sc2Al3O12 crystal were investigated and compared with those from Yb:YAG crystals. The broad absorption and emission spectra of Yb:Y3Sc2Al3O12 show that this crystal is very suitable for laser-diode pumping and ultrafast laser pulse generation. Laser-diode pumped continuous-wave and passively Q-switched Yb:Y3Sc2Al3O12 lasers with Cr4+: YAG crystals as saturable absorber have been demonstrated for the first time. Continuous-wave output power of 1.12 W around 1032 nm ( multi-longitudinal modes) was measured with an optical-to-optical efficiency of 30%. Laser pulses with pulse energy of over 31 mu J and pulse width of 2.5 ns were measured at repetition rate of over 12.7 kHz; a corresponding peak power of over 12 kW was obtained. The longitudinal mode selection by a thin plate of Cr4+: YAG as an intracavity etalon was also observed in passively Q-switched Yb:Y3Sc2Al2O12 microchip lasers. (C) 2008 Optical Society of America

Composite Yb : YAG/Cr4+: YAG ceramics picosecond microchip lasers

Efficient laser-diode pumped picosecond self-Q-switched all-ceramic composite Yb: YAG/ Cr4+: YAG microchip lasers with 0.72 MW peak power has been developed. Lasers with nearly diffraction-limited beam quality (M-2 < 1.09), oscillate at stable single- and multi- longitudinal-modes due to the combined etalon effects in the Yb:YAG and Cr4(+:) YAG parts of its binary structure. (C) 2007 Optical Society of America

Effect of ytterbium concentration on Yb : YAG microchip laser performance at ambient temperature

The microchip laser performance of Yb:YAG crystals doped with different ytterbium concentrations (10, 15, and 20 at.%) has been investigated at ambient temperature. Efficient laser oscillation for 1-mm-thick YAG doped with 10 at.% Yb3+ ions was achieved at 1030 and 1049 nm with slope efficiencies of 85 and 81%, correspondingly

Stimulated Raman Scattering (SRS) in α‐AlOOH (Diaspore)

In single crystals of orthorhombic α‐AlOOH, known also as mineral diaspore, χ(3)‐nonlinear lasing by stimulated Raman scattering (SRS) and Raman‐induced four‐wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 µm wavelength produces a broadband Stokes and anti‐Stokes frequency comb with up to 25 SRS‐ and RFWM‐generated emission lines. All observed Stokes and anti‐Stokes lasing components in the visible and near‐IR are identified and attributed to a single SRS‐promoting vibration mode with ωSRS ≈ 445 cm−1. The first Stokes steady‐state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW−1

Laser-diode pumped heavy-doped Yb : YAG ceramic lasers

Laser performance of heavy-doped Yb:YAG ceramics was investigated using a two-pass pumping miniature laser configuration. Slope efficiency of 52% and optical-to-optical efficiency of 48% have been achieved for 1-mm-thick YAG ceramic doped with 20 at. % ytterbium ions. Laser spectra of Yb:YAG ceramic and single-crystal lasers were addressed under different intracavity laser intensities. Heavy-doped Yb:YAG ceramic is more suitable for a thin disk laser than a single-crystal with the same Yb3+-ion lasants. (c) 2007 Optical Society of America

Ytterbium and chromium doped composite Y3Al5O12 ceramics self-Q-switched laser

Composite Yb:Y3Al5O12/Cr:Y3Al5O12 ceramics were fabricated by using vacuum sintering technique and nanocrystalline technology. Self-Q-switched composite Yb:Y3Al5O12/Cr:Y3Al5O12 ceramic lasers with pulse energy of 125 mu J and peak power of over 105 kW at repetition rate of 3.8 kHz have been demonstrated. Nearly diffraction-limited beam quality with M-2 less than 1.35 was achieved in this composite Yb:Y3Al5O12/Cr:Y3Al5O12 ceramic self-Q-switched lasers. (C) 2007 American Institute of Physics

Near-diffraction-limited passively Q-switched Yb : Y3Al5O12 ceramic lasers with peak power > 150 kW

Laser-diode pumped nearly diffraction-limited beam quality (M-2 < 1.05), high peak power, subnanosecond passively Q-switched Yb:Y3Al5O12 ceramic miniature laser with Cr4+:Y3Al5O12 ceramic as saturable absorber has been achieved. The slope efficiency is as high as 36% for 80% initial transmission of Cr4+:Y3Al5O12 ceramic. The pulse width of 335 ps and peak power of over 150 kW at repetition rate of 5 kHz were obtained. Laser oscillates at single-longitudinal-mode oscillation and wide-separated multilongitudinal-mode oscillation due to the combined etalon effect of the Cr4+:YAG thin plate and thin glass plate as output coupler. (c) 2007 American Institute of Physics

Achievements of modern crystal-laser physics

This review summarizes the current understanding of the physics of crystalline laser materials. After a brief historical overview, the host crystals and activator ions are examined. This information is organized both by host crystal and by activator ion in order to show the relationships of laser action to host and activator properties. Particular attention is placed on the latest results in the search for new rare-earth and transition-metal activator ions and on the role of crystal-field disorder in the optical properties of Ln3+ ions in insulating laser crystals. The research on crystalline laser hosts for obtaining stimulated emission from Ln3+ activator ions at new wavelengths is also summarized