Juan Gong

Room-temperature diode-pumped Yb, Na: PbF2 laser

Growth, spectroscopic properties, and laser performance of Yb, Na:PbF(2) crystals have been investigated. With a 2 mol.% Yb(3+)-doped sample we obtained 2.65 W output power at 1045 nm for 7.5 W of incident power at 976 nm. The laser wavelength could be tuned from 1017 to 1078 nm, showing the great potential of Yb, Na:PbF(2) as an amplifier medium for femtosecond pulses.

A Nd:MgO:LiTaO3 crystal as a gain medium for 1083?nm lasers

The growth, spectroscopic properties, laser parameters, and laser performance of a Nd3+/Mg2+ co-doped congruent LiTaO3 crystal were investigated. Continuous-wave (cw) laser operation at a wavelength of about 1083?nm with a slope efficiency of nearly 12% was achieved. The maximum cw output power obtained was 615?mW, which, to the best of our knowledge, is the highest output power obtained for this crystal thus far. We propose that Nd:MgO:LiTaO3 lasers could be an excellent source for the optical pumping of helium, and may achieve second harmonic generation and optical parametric oscillation in the same crystal.

Optical properties of Tm, Mg:LiTaO3 laser crystal

A Tm, Mg co-doped LiTaO3 crystal has been grown by Czochralski method. Room temperature polarized absorption spectra and fluorescence spectrum of the Tm, Mg:LiTaO3 crystal were measured and analyzed. The maximum absorption cross-section is 6.0791 × 10−20 cm2 at around 790 nm with full width at half maximum of 5 nm. The emission cross-section of 3F4 manifold was 2.2 × 10−20 cm2. The spectroscopic parameters of Tm3+ ion were calculated by applying the Judd-Ofelt approach, and the intensity parameters Ω2, Ω4, and Ω6 were obtained to be 7.71 × 10−20, 1.09 × 10−20, and 1.16 × 10−20 cm2, respectively. The branching ratios and radiative lifetimes were also presented and the radiative lifetime of Tm3+3F4 → 3H6 transition is 968.3 μs. The results were also analyzed and compared with other Tm3+ doped hosts.

Crystal growth, spectroscopic characterization and laser operation of Tm3+ and Ho3+ codoped LiLuF4 crystal

Laser crystal Tm3+ and Ho3+ codoped LiLuF4 with high optical quality was grown by Czochralski technique. Its absorption and fluorescence spectra were investigated. A continuous wave output power of 1.12 W at 2066 nm was obtained with a slope efficiency of 24% by use of diode pumping. In the Q-switched mode, a slope efficiency of 18.9% and a maximum average power of 0.65 W were obtained.

Spectroscopic characterization and diode-pumped 910 nm laser of Nd:LiLuF4 crystal

Polarized absorption and fluorescence spectra Nd3+-doped LiLuF4 single crystal were investigated. The peak emission cross section at 905 and 910 nm are 0.97 × 10−20 and 0.82 × 10−20 cm2, respectively. Two samples with different dimensions were tested in the laser experiments. With a laser-diode as the pump source, a maximum 1.17 W laser output at 910 nm has been obtained with a slope efficiency of 16.3% with respect to the pump power.

Transition intensities and excited state relaxation dynamics of Tm3+ in Tm:PbF2 crystal

High-quality Tm doped β-PbF2 crystal is grown by the Bridgman method in a nonvacuum atmosphere. Optical absorption spectra were acquired and analysed in the framework of the Judd-Ofelt theory. Values of radiative transition rates and luminescence branching ratios calculated using phenomenological intensity parameters Ωλ were compared to corresponding experimental values derived from measurement of luminescence spectra and decay curves. The emission cross-sections of the 3F4 → 3H6 transitions of the Tm3+ ions at 1.86 μm wavelengths were estimated by the use of the Fuchtbauer-Ladengurg method.

Optical spectroscopy of Nd3+Mg2+ co-doped LiTaO3 laser crystal

A Nd3+ and Mg2+ co-doped LiTaO3 single crystal has been grown successfully by the Czochralski method. The polarized absorption spectra of the crystal were measured and investigated. The peak absorption cross-sections at 806 and 810?nm were 4.17???10?20?cm2 and 4.47???10?20?cm2 with a full width at half maximum of 29 and 17?nm for ?-?and ?-polarization, respectively. Based on the Judd?Ofelt theory, the spectral parameters of Nd3+ in the as-grown crystal were investigated in detail. Moreover, the emission probabilities, branching ratio and radiative lifetime for the transitions from 4F3/2 were calculated. The radiative lifetime of 4F3/2 was calculated to be 159??s and the luminescent quantum efficiency of the 4F3/2 manifold was about 81.13%. The results were also compared with other Nd3+ doped crystals.

Crystal growth, spectral and laser properties of Nd:LSAT single crystal

Nd:(La, Sr)(Al, Ta)O3 (Nd:LSAT) crystal was grown by the Czochralski method. The absorption and fluorescence spectra of Nd:LSAT crystal at room temperature were investigated. With a fiber-coupled diode laser as pump source, the continuous-wave (CW) laser action of Nd:LSAT crystal was demonstrated. The result of diode-pumped laser operation of Nd:LSAT crystal single crystal is reported for what is to our knowledge the first time. The maximum output power at 1064 nm was obtained to be 165 mW under the incident pump power of 3 W, with the slope efficiency 10.9%.