Gérard Aka

240 kW peak power at 266 nm in nonlinear YAl 3 (BO 3 ) 4 single crystal

We report the fourth harmonic generation at 266 nm using a type I YAl3(BO3)4 (YAB) single crystal from a Q-switch microchip laser Nd:YAG/Cr⁴⁺:YAG frequency doubled with a LiB3O5 (LBO) crystal. 240 kW peak power at 266 nm corresponding to a mean conversion efficiency of 12.2% from 532 to 266 nm has been obtained with a 2.94 mm thick YAB crystal. The influences of optical homogeneity and absorption on the conversion efficiency are discussed.

Dielectric frame, Sellmeier equations, and phase-matching properties of the monoclinic acentric crystal GdCa 4 O(BO 3 ) 3

We directly measured the phase-matching properties of the biaxial GdCa4O(BO3)3 (GdCOB) crystal using the sphere method. We studied second-harmonic generation and difference frequency generation in two principal planes of the crystal. All these data allowed us to refine the Sellmeier equations of the three principal refractive indices. These equations are valid over the entire transparency range of GdCOB and then could be used to calculate the tuning curves of infrared optical parametric generation.

Rise in power of Yb:YCOB for green light generation by self-frequency doubling

Spectroscopic properties and self-frequency-doubling laser performance are presented for Yb:YCa4O(BO3)3 (Yb:YCOB) crystals oriented for type I second-harmonic generation in the ZX plane. In a plane-concave cavity 10xa0cm long, up to 330xa0mW of green light (544.5xa0nm) is obtained for 14.7xa0W of laser diode incident pump power. Broad emission bands and weak anisotropy in the 1060-1100xa0nm range between the two eigenstates of polarization may explain the instability of the self-frequency-doubled output power.

Crystal growth, spectroscopy and laser performances of Pr 3+ :Sr 0.7 La 0.3 Mg 0.3 Al 11.7 O 19 (Pr:ASL)

We report on the crystal growth, spectroscopic properties and visible laser performances of Pr3+-doped Sr0.7La0.3Mg0.3Al11.7O19 (ASL). ASL crystals doped with 2 at.% and 4 at.% Pr3+ were grown by Czochralski method. The laser experiments were carried out in a plane-concave resonator under excitation at 486 nm, provided from a 2ω-OPSL. Efficient laser emission was obtained with an 8 mm long sample of Pr(2at.%):ASL. The maximum output power amounted to 267 mW, 52 mW, and 318 mW at an absorbed power of 1.2W for red, orange, and deep red emission, respectively.