F. Druon

Diode-pumped Yb:Sr(3)Y(BO(3))(3) femtosecond laser.

We have developed a diode-pumped Yb(3+)Sr(3)Y(BO(3))(3) (Yb:BOYS) laser generating 69-fs pulses, at a central wavelength of 1062 nm. This laser is mode locked by use of a semiconductor saturable-absorber mirror and emits 80 mW of average power at 113 MHz. This is, to our knowledge, the first mode-locked Yb:BOYS laser and the shortest duration obtained from an ytterbium laser with a crystalline host. The central wavelength can be tuned from 1051 to 1070 nm, for sub-100-fs pulses. We have also achieved an average power as high as 300 mW with pulse duration of 86 fs at 1068 nm.

Spectroscopy and efficient laser action from diode pumping of a new broadly tunable crystal: Yb 3+ :Sr 3 Y(BO 3 ) 3

The first demonstration of laser action in a Yb3+:Sr3Y(BO3)3 crystal is reported. This new material exhibits particularly broad absorption and emission bandwidths (6 and 60 nm, respectively) and hence is of particular interest for diode-pumped femtosecond and tunable laser sources. Efficient operation from diode pumping (1.4 W of cw laser power obtained with 3.6 W of diode pump power and as much as 3.4 W of peak power from high-power quasi-cw pumping) together with smooth tunability (over 50 nm FWHM) is reported. For the comparison, efficiency and thermal limitations of Yb:glass and Yb:Ca4GdO(BO3)3 have been investigated under the same conditions.

Spectroscopic properties and laser performances of Yb:YCOB and potential of the Yb:LaCOB material

Abstract In order to increase the compacity of the Yb-doped lasers, YCOB (Ca 4 Y(BO 3 ) 3 ) materials with high ytterbium concentration have been characterized. Large 15 at.% and 35 at.% ytterbium-doped single crystals were grown by the Czochralski pulling method. Spectroscopic and laser properties have been investigated and laser tests performed under titanium sapphire and diode pumping at 976 nm. Low thresholds under Ti:Sa pumping (50 mW) and high slope efficiency under diode pumping (66%) have been obtained. The optical quality and the distribution of Yb 3+ dopant through the highly doped crystals is discussed. First results on the Yb:LaCOB crystals grown by the Czochralski process, containing 46Yb 3+ at.%, are also presented.

Apatite-structure crystal, Yb 3+ :SrY 4 (SiO 4 ) 3 O, for the development of diode-pumped femtosecond lasers

We report what is believed to be the first diode-pumped Yb(3+): SrY(4)(SiO(4)) (3)O laser. We investigate both the cw and the mode-locked regimes. In the cw regime an average output power of 1.05 W is demonstrated for 3.6 W of incident pump power. In the femtosecond regime a pulse duration of 94 fs for an average power of 110 mW is obtained at a central wavelength of 1068 nm. This is, to our knowledge, the first femtosecond mode-locked oscillator made with an Yb-doped apatitelike crystal. These properties are related to the unique spectroscopic properties of Yb(3+) ions in this atypical apatite-family crystal.

Thermal lensing measurements in diode-pumped Yb-doped GdCOB, YCOB, YSO, YAG and KGW

A Shack–Hartmann wavefront sensor was used to measure thermal lensing in diode-end-pumped Yb-doped GdCOB, YCOB, YSO, YAG, and KGW crystals, under lasing or nonlasing conditions. Measured thermal lenses are aberration-free, and their focal lengths under lasing action range from 40 to 140 mm for 5 W of absorbed power. When laser action was inhibited the thermal lens dioptric power was increased significantly in most crystals, supplying evidence that nonradiative mechanisms exist. Reduction of thermal effects in a composite YCOB crystal is also investigated, as well as the dependence of thermal lensing on the emission wavelength in YSO. 2002 Elsevier Science B.V. All rights reserved.

High-repetition-rate 300-ps pulsed ultraviolet source with a passively Q-switched microchip laser and a multipass amplifier.

We demonstrate a new kind of picosecond laser source in the UV at a high repetition rate of -45 kHz , using only passive, compact, and simple elements. This system is based on a microchip laser and a very efficient multipass amplifier, both pumped with recently developed high-brightness laser diodes. The system has been optimized to deliver, at a high repetition rate, subnanosecond pulses at the wavelength 355 nm with an energy per pulse of close to 1 muJ (38-mW average power). This source is to our knowledge the first totally passive 300-ps UV laser source at this high repetition rate.

Diode-pumped continuous-wave and femtosecond laser operations of a heterocomposite crystal Yb 3+ :SrY 4 (SiO 4 ) 3 O?Y 2 Al 5 O 12

We report cw and femtosecond laser operations under diode pumping of a diffusion-bonding heterocomposite Yb-doped crystal: Yb3+:SrY4(SiO4)3O parallel Y2Al5O12(YAG paralell SYS:Yb). To show the advantages of this heterocomposite crystal over classical Yb:SYS crystal, we first investigate the high-power cw regime. A cw power of 4.3 W is demonstrated. The femtosecond regime is also investigated, and 1-W-average-power, 130-fs pulses at 1070 nm are produced, which represents, to our knowledge, the first demonstration of an Yb-doped heterocomposite mode-locked laser.

ILE 25PW single laser beamline: The French step for the European Extreme Light Infrastructure (ELI)

We present the design of a single ultra intense laser beamline delivering 25PW pulses at one shot per minute as a first step of an ultra intense high field science European project (extreme light infrastructure).

Diode-pumped operation of Yb:GGG laser

Summary form only given. We demonstrated efficient diode-pumped operation of Yb:GGG. 1.85 W of laser power at 1022 nm was obtained, with a small-signal gain of 2.26. Quite similar to YAG as far as spectroscopic and thermal properties are concerned, it might be a reliable competitor of the latter for high power laser systems.

Multiwatt and broadly tunable laser action from diode-pumping of two silicate ytterbium-doped crystals: Yb:Y/sub 2/SiO/sub 5/ and Yb:SrY/sub 4/(SiO/sub 4/)/sub 3/O

Ytterbium-doped materials are competitors of neodymium-doped materials for high power diode-pumped lasers. Furthermore, some materials exhibit ultrabroad emission spectra, which makes them suitable for tunable or ultrafast sources around 1 /spl mu/m. The high power and tunable cw laser action in Yb:Y/sub 2/SiO/sub 5/ (YSO), and then in a composite crystal made of Yb:SrY/sub 4/(SiO/sub 4/)/sub 3/O (Yb:SYS) diffusion-bonded on an undoped YAG crystal. The pump source is a fiber-coupled laser diode emitting 13.5 W at the zero-line wavelength (977 nm for Yb:YSO and 979 nm for Yb:SYS). The resonator is a 3-mirror cavity designed to support only TEM/sub 00/ oscillation.