Mathieu Jacquemet

High power diode-pumped Yb3+:CaF2 femtosecond laser

We report what is believed to be the first demonstration of a high-power passively mode-locked diode-pumped femtosecond laser based on an Yb3+:CaF2 single crystal, directly pumped by a 15-W fiber-coupled laser diode. With a 5-at. % Yb3+ -doped sample and prisms for dispersion compensation we obtained pulses as short as 150 fs, with 880 mW of average power and up to 1.4-W average output power, with a pulse duration of 220 fs, centered at 1049 nm. The laser wavelength could be tuned from 1040 to 1053 nm in the femtosecond regime. Using chirped mirrors for dispersion compensation, the oscillator provided up to 1.74 W of average power, with a pulse duration of 230 fs, corresponding to a pulse energy of 20 nJ and a peak power of 85 kW.

Efficient diode-pumped Yb 3+ :Y 2 SiO 5 and Yb 3+ :Lu 2 SiO 5 high-power femtosecond laser operation

We report the mode-locked operation of two new Yb-doped oxyorthosilicates, Y2SiO5 (YSO) and Lu2SiO5 (LSO), that are longitudinally diode pumped. Yb:YSO supplied pulses as short as 122 fs with 410 mW of output power at 1041 nm. More than 2.6 W of average output power, for pulse durations of 198 fs at 1044 nm and 260 fs at 1059 nm for Yb:YSO and Yb:LSO, respectively, were provided. These are, to our best knowledge, the highest values ever obtained and the most efficient mode-locked laser in such a classic fiber-coupled diode-pumping configuration.

High power tunable diode-pumped Yb3+:CaF2 laser

Results of diode-pumped cw laser operation of an Yb3+:CaF2 single crystal are reported for what is to our knowledge the first time. With a 5-at.% Yb3+ -doped sample we obtained 5.8-W output power at 1053 nm for 15 W of incident power at 980 nm. The laser wavelength could be tuned from 1018 to 1072 nm, and a small-signal gain as high as 1.8 was achieved, showing the great potential of Yb3+:CaF2 as an amplifier medium for femtosecond pulses.

Blue-green single-frequency laser based on intracavity frequency doubling of a diode-pumped Ytterbium-doped laser.

Single-frequency lasers in the blue-green (500 nm) visible spectrum are important for many applications including iodine precision spectroscopy, optical frequency standards or ionized argon lasers substitution. To the best of our knowledge, we report in this paper the first single-frequency diode-pumped Ytterbium-doped solid-state laser operating at 501.7 nm by intracavity second harmonic generation (SHG). The single-frequency fundamental infrared laser light is generated by a diode-pumped Yb3+:Y2SiO5 crystal in a ring oscillator. Intracavity SHG with a KNbO3 nonlinear crystal produced more than 50 mW of single-frequency blue-green radiation.

Single-Frequency High-Power Continuous-Wave Oscillation at 1003 nm of an Optically Pumped Semiconductor Laser

This work reports single-frequency laser oscillation at λ = 1003.4 nm of an optically pumped external cavity semiconductor laser. By using a gain structure bonded onto a high conductivity substrate, we demonstrate both theoretically and experimentally the strong reduction of the thermal resistance of the active semiconductor medium, resulting in a high power laser emission. The spectro-temporal dynamics of the laser is also explained. Furthermore, an intracavity frequency-doubling crystal was used to obtain a stable single-mode generation of blue (λ = 501.5 nm) with an output power around 60 mW.

Kilometric Path Lengths in Infrared Absorption with Time-Resolved Fourier Transform Spectroscopy

Time-resolved Fourier transform spectroscopy associated to intracavity laser absorption allows to record highly sensitive high resolution spectra, in the infrared up to 2.5 µm, of both stable and unstable molecules.

High power diode pumped femtosecond laser based on ytterbium doped YSO and LSO crystals

Ytterbium-doped yttrium and lutetium oxyorthosilicate (Yb:Y/sub 2/SiO/sub 5/ and Yb:Lu/sub 2/SiO/sub 5/) crystals are now well-known to be particularly suitable for directly diode-pumped solid-state lasers which leads to robust, compact and efficient devices. For the well-known reasons of simple electronic structure, suitability with high-power InGaAs laser diodes, good thermal conductivity on the one hand, and the broad emission bands of Yb/sup 3+/ in some matrices on the other one they seem particularly well suited for the efficient generation (few hundreds milliwatts) of ultra-short laser pulses.

Single-frequency operation at 1003.4 nm with Yb:YSO: toward the first diode-pumped solid state aquamarine (501.7 nm) laser

Single-frequency IR and visible lasers are of a great interest in many research and application fields. We present in this paper, what we believe to be, to the best of our knowledge, the first diode-pumped Ytterbium-doped solid-state laser emitting at 1003.4 nm in single-frequency operation and first results obtained in the blue-green region by second harmonic generation (SHG). The laser is based on an diode-pumped Yb:YSO (Yb:Y2SiO5) crystal. The choice of an Yb-doped crystal, pumped at 978 nm, involves two main constraints. First, the small difference, between pump and laser wavelengths, prevents the use of suitable standard dichroic mirrors. Secondly, due to the quasi-three level transition, reabsorption is significant around 1 μm and pump-absorption has to be highly saturated all along the crystal length. The pump source is a single-emitter laser diode providing a maximum power of 4 W at 978 nm. The resonator is a six-mirror ring-cavity containing a Faraday rotator to obtain unidirectional operation. A thin Fabry-Perot etalon at Brewster angle is used to maintain linear polarization as well as finely tune the laser wavelength. More than 300 mW of single-frequency radiation at 1003.4 nm has been obtained for 3.2 W of incident pump power. First intracavity SHG results are also presented using a KNbO3 nonlinear crystal at 76.5 °C to operate in non-critical phase-matching. In this configuration, 300 mW of IR radiation and 14 mW of aquamarine wavelength (501.7 nm) have simultaneously been obtained at room temperature in single-frequency operation.

High-power CW diode-pumped laser operation of Yb 3+ :CaF 2 crystal

We present here the first CW high power laser operation obtained under diode-pumping with an Yb3+:CaF2 crystal. This crystal exhibits good thermo-optical properties and can easily be grown in bulk crystals or in thin films. A maximum power of 5.8 W in a diffraction limited beam has been obtained with a 5% ytterbium-doped crystal of 4 mm-long. Moreover, the laser wavelength has been tuned over 54 nm, between 1018 and 1072 nm, and the double-pass small-signal gain has been measured to be more than 1.8, showing the great potential of Yb3+:CaF2 as a gain media for ultra-short pulses operation or as amplifier.

Single-mode operation at 1003.4 nm with Yb:YSO.

Single-mode laser emission at 1003.4 nm with an ytterbium-doped crystal (Yb:YSO) is reported for the first time under diode pumping at 978 nm. An off-axis pumping scheme allows to reach a quantum defect of about 2.5%. The laser wavelength can be tune on about 4 nm around 1004 nm in single-frequency operation. A power of 190 mW at 1003.4 nm was obtained.