Alexsei A. Pavlyuk

Monoclinic Tungstates KDy(WO 4) 2 and KLu(WO 4) 2 - New χ( 3)-Active Crystals for Laser Raman Shifters

Efficient high-order Stokes and anti-Stokes generation in the visible and near infrared (NIR) in monoclinic KDy(WO4)2 and KLu(WO4)2 1aser host crystals by stimulated Raman scattering (SRS) and Raman-induced four-wave mixing (RFWM) were observed at 300 K for the first time in the single-pass geometry under picosecond excitation. All scattering components were identified and connected with the SRS-active vibration modes of these tungstates.

Femtosecond continuously tunable second harmonic generation over the entire-visible range in orthorhombic acentric Gd2(MoO4)3 crystals

Second harmonic generation over the entire visible range in Nd3+ doped and undoped Gd2(MoO4)3 crystals under ultrashort hypercontinuum pumping is presented. The continuous tuning ranges from 487 to 790 nm in a single crystal.

Luminescent and lasing characteristics of heavily doped Yb{sup 3+}:KY(WO{sub 4}){sub 2} crystals

The luminescence decay times are measured taking into account reabsorption for KY(WO4)2:Yb(KYW:Yb) crystals with atomic concentrations of active ions from 0.2% to 30%. The radiative lifetime of Yb3+ ions was measured to be 233 μs. The cw output power of 1.46 and 1.62 W was achieved with the slope efficiency 52% and 47% for Yb:KYW lasers with the atomic concentration of Yb3+ ions equal to 10% and 30%, respectively. Using a semiconductor mirror with a saturable absorber (SESAM) in the passive mode-locking regime, pulses of duration 194 and 180 fs were obtained at wavelengths of 1042 and 1039 nm for crystals with Yb3+ concentrations equal to 10% and 30%, respectively, the average output power being 0.63 and 0.75 W.The luminescence decay times are measured taking into account reabsorption for KY(WO{sub 4}){sub 2}:Yb(KYW:Yb) crystals with atomic concentrations of active ions from 0.2% to 30%. The radiative lifetime of Yb{sup 3+} ions was measured to be 233 {mu}s. The cw output power of 1.46 and 1.62 W was achieved with the slope efficiency 52% and 47% for Yb:KYW lasers with the atomic concentration of Yb{sup 3+} ions equal to 10% and 30%, respectively. Using a semiconductor mirror with a saturable absorber (SESAM) in the passive mode-locking regime, pulses of duration 194 and 180 fs were obtained at wavelengths of 1042 and 1039 nm for crystals with Yb{sup 3+} concentrations equal to 10% and 30%, respectively, the average output power being 0.63 and 0.75 W. (lasers and amplifiers)

Effect of the Concentration of Nd3+Ions in KGd(WO4)2: Nd3+Crystals on Laser Characteristics

Active KGd(WO4)2: Nd3+elements used in laser engineering have typical concentrations of Nd3+ions of ∼3 at. %. Our studies have shown that the optimal concentration is close to 4.5 at. %. This result is confirmed for active elements 3 mm in diameter and 50 mm long in two lasing modes at a wavelength of 1.067 μm and in the stimulated Raman scattering (SRS) self-conversion mode at 1.538 μm in a lamp-pumped laser.