The authors report on the performance of an Yb-doped, 100μm core rodlike photonic crystal fiber (PCF) used as the final amplifier in a gain-staged master-oscillator/power-amplifier source. From the PCF, they obtained 1-ns-long pulses of energy in excess of 4.3mJ, peak/average power ∼4.5MW∕42W, and spectral linewidth ∼20GHz. The PCF emitted a beam exhibiting near-Gaussian, single-transverse-mode profile of M2∼1.3.

We report on the generation of mid-infrared Kerr frequency combs in high-finesse CaF2 and MgF2 whispering-gallery-mode resonators pumped with continuous-wave room-temperature quantum cascade lasers. The combs were centered at 4.5 μm, the longest wavelength to date. A frequency comb wider than one half of an octave was demonstrated when approximately 20 mW of pump power was coupled to an MgF2 resonator characterized with quality factor exceeding 10(8).

We report on a diode-pumped master-oscillator/fiber-amplifier (MOFA) system consisting of a passively Q-switched, single-frequency Nd:LSB microchip laser that seeds a dual-stage Yb-doped fiber amplifier. A large-core, single-mode photonic crystal fiber was used for the final amplifier. The MOFA generated 1062nm wavelength, 1-ns long, ~10kHz repetition-rate, diffraction-limited pulses of energy >1mJ, peak power >1MW, average power >10W, and spectral linewidth ~9 GHz.

We report a multimode, double-clad, Yb-doped fiber amplifier that produces diffraction-limited, 0.8-ns pulses with energies of 255 muJ and peak powers in excess of 300 kW at a repetition rate of ~8 kHz . Single-transverse-mode operation was obtained by bend-loss-induced mode filtering of the gain fiber.