Anaël Jaffrès

Sub-100-fs Yb:CALGO nonlinear regenerative amplifier

We report on the first diode-pumped Yb:CaGdAlO4 regenerative amplifier in the sub-100-fs regime. It generates pulses at a central wavelength of 1047 nm with up to 24 μJ energy (after compression) at a repetition rate of 50 kHz. The measured pulse duration is 97 fs, with a spectral bandwidth of 19 nm. We describe in detail how nonlinear effects are optimally used to compensate gain narrowing in order to overcome the 100 fs barrier.

Magic mode switching in Yb:CaGdAlO 4 laser under high pump power

We present unique spatial-mode switching in a cw Yb:CALGO laser when pumped at a multihundred-watts power level. It permits us to automatically stabilize to a TEM(00) mode from a highly spatial multimode regime. This stabilization is achievable thanks to polarization-mode switching allowed by the particular spectroscopic and thermal properties of Yb:CALGO crystal. This atypical and unexpected behavior is studied in detail in this Letter and explained by analysis of the thermo-optical coefficients for CALGO.

CW diode pumped Er, Yb, Ce:CAS single crystal 1.5 μm laser

Crystal growth, spectroscopic investigations and laser characterization of Er3+, Yb3+, and Ce3+ co-doped Ca2Al2SiO7 (CAS) crystal were realized. The Er3+–Yb3+ energy transfer efficiency in CAS crystal was found to be around 75–78%. 275 mW of CW power at 1555 nm was demonstrated for the first time with a single crystal under diode pumping. The achieved differential slope efficiency was closed to 10%. Er3+, Yb3+, Ce3+: CAS appears as one of the most promising crystalline hosts for 1.5 µm laser emission, when compared to other crystals of the literature.

Spectroscopic properties of newly flux grown RE2O3:Yb3+ (RE=Y,Lu) laser crystals for high-power diode-pumped systems

Developing large laser grade cubic rare-earth sesquioxides (RE2O3, RE=Y,Sc,Lu) single crystals doped with Yb3+ ions stands as one of the most challenging endeavours of todays crystal growth1,2. Recent studies on cubic RE2O3 single crystals have demonstrated their laser potential and highlighted the extreme thermodynamic conditions in which their growth takes place1-3. In particular, the laser performances of Lu2O3:Yb3+ crystals make them likely to outperform betterknown rivals such as YAG:Yb3+ or KY(WO4)2:Yb3+ for 976 nm diode-pumped systems4. Several mm3-sized Yb3+-doped Y2O3, Gd2O3 and Lu2O3 single crystals were recently grown by a newly designed high-temperature solution growth method5, and characterized by means of X-ray diffraction, Fourier transformed infrared (FTIR) spectroscopy and electron probe microanalysis (EPMA). Spectroscopic characterizations (absorption and emission cross sections, visible anti-Stokes emission, fluorescence decays) of these new cubic RE2O3:Yb3+ (RE=Y,Lu) single crystals are presented.

Generation of sub-100-fs pulses in an Yb: CaGdAlO4 regenerative amplifier by tailored control of linear and nonlinear phase

Generation of sub 100 fs pulse has been obtained in an Yb:CALGO regenerative amplifier using nonlinear effects. It exhibits 97fs pulses at 1047nm with up to 24μJ energy with a spectral bandwidth of 19nm.

Yb:CaGdAlO4 laser under high pumping power: high performances and singularities

We present some anisotropy properties of the Yb:CALGO with a spatial mode switching when pumped in the multihundred watts of power. This allows to automatically stabilize a TEM00 mode from highly spatial-multimode regime. This stabilization is achievable thanks to a polarization mode switching allowed by the particular anisotropic spectroscopy and thermal properties of Yb:CALGO.

Generation of sub-100 fs pulses in a Yb:CALGO regenerative amplifier

Ultra short pulse down to 100 fs has been obtained in a regenerative amplifier using Yb doped CALGO crystals. By employment of nonlinearity we succeed to overcome gain narrowing limitation.

CW and Q-Switched diode-pumped Laser operation in Er 3+ , Yb 3+ , Ce 3+ : Ca 2 Al 2 SiO 7 single crystal at 1.5-1.6 μm

First demonstration of actively Q-Switched laser operation in Er, Yb, Ce:Ca2Al2SiO7 under diode-pumping in safe eye range is realized. Comparison is done with commercial phosphate glass.

High power cw and fs Yb:CALGO thin-disk laser using diamond heat spreader

We present the study and results on high-power oscillators based on Yb:CALGO in thin-disk laser architecture using a diamond heat spreader for thermal management both in cw (spatially multimode and single-mode) and in femtosecond regime.