Yb:YAG single-crystal fiber amplifiers for picosecond lasers using the divided pulse amplification technique.

A two-stage master-oscillator power-amplifier (MOPA) system based on Yb:YAG single-crystal-fiber (SCF) technology and designed for high peak power is studied to significantly increase the pulse energy of a low-power picosecond laser. The first SCF amplifier has been designed for high gain. Using a gain medium optimized in terms of doping concentration and length, an optical gain of 32 dB has been demonstrated.

High-power Yb:YAG single-crystal fiber amplifiers for femtosecond lasers in cylindrical polarization.

We demonstrate a three-stage diode-pumped Yb:YAG single-crystal-fiber amplifier to generate femtosecond pulses at high average powers with linear or cylindrical (i.e., radial or azimuthal) polarization.

Deep-UV 236.5 nm laser by fourth-harmonic generation of a single-crystal fiber Nd:YAG oscillator.

We demonstrate a deep-UV laser at 236.5 nm based on extracavity fourth-harmonic generation of a Q-switched Nd:YAG single-crystal fiber laser at 946 nm. We first compare two nonlinear crystals available for second-harmonic generation: LBO and BiBO.

3 W, 300 μJ, 25 ns pulsed 473 nm blue laser based on actively Q-switched Nd:YAG single-crystal fiber oscillator at 946 nm.

We report the realization of a frequency doubled, actively Q-switched and polarized oscillator based on Nd:YAG single-crystal fiber. A laser output of 8 W, 10 kHz, and 30 ns at 946 nm is reported. The laser is extracavity frequency doubled in a BiBO crystal to obtain 3 W and 300 μJ of blue laser with a beam quality of M(2)y=1.

Yb:YAG single crystal fiber power amplifier for femtosecond sources.

We demonstrate a versatile femtosecond power amplifier using a Yb:YAG single crystal fiber operating from 10 kHz to 10 MHz. For a total pump power of 75 W, up to 30 W is generated from the double-pass power amplifier. At a repetition rate of 10 kHz, an output energy of 1 mJ is obtained after recompression.

Nd:YAG single-crystal fiber as high peak power amplifier of pulses below one nanosecond.

We explore the potential of Nd:YAG single-crystal fibers for the amplification of passively Q-switched microlasers operating below 1 ns. Different regimes are tested in single or double pass configurations. For high gain and high power amplification this novel gain medium provided average powers up to 20 W at high repetition rate (over 40 kHz) for a pulse duration of 1 ns.

Direct amplification of ultrashort pulses in μ-pulling-down Yb:YAG single crystal fibers.

We demonstrated that Yb:YAG single crystal fibers have a strong potential for the amplification of femtosecond pulses. Seeded by 230 fs pulses with an average power of 400 mW at 30 MHz delivered by a passively mode-locked Yb:KYW oscillator, the system produced 330 fs pulses with an average power of 12 W. This is the shortest pulse duration ever produced by an Yb:YAG amplifier.

Nonlinear compression in a rod-type fiber for high energy ultrashort pulse generation.

We report the use of nonlinear compression in a very large mode-area rod-type photonic crystal fiber. This fiber allows the use of high energy pulses in the few microjoule range. We demonstrate the compression of 4 microJ, 338 fs pulses from a fiber chirped pulse amplification (FCPA) system down to 49 fs, 41 MW peak power pulses at a repetition rate of 200 kHz with an average power of 400 mW.