Electro-optic comb pumped optical parametric oscillator with flexible repetition rate at GHz level.

We present a gigahertz (GHz)-repetition-rate optical parametric oscillator (OPO) pumped by an electro-optic comb at 1.03 µm, delivering sub-picosecond signal pulses across 1.5-1.7 µm from a MgO-doped periodically poled LiNbO3 crystal. Using a pump power of 5 W at 14.2 GHz repetition rate, 378 mW of signal power is obtained at 1.52 µm from a subharmonic cavity, corresponding to a signal extraction efficiency of 7.6%. By cascading a Mach-Zehnder modulator, the pump pulse repetition rate can be divided by any integer number from one to 14, allowing the OPO to operate with a flexible repetition rate from 1 to 14.2 GHz. A strategy leading to quasi-continuous repetition rate tunability of the OPO is also discussed.

Millijoule-class Yb-doped pulsed fiber laser operating at 977 nm.

We report what we believe to be the first millijoule-class ytterbium-doped fiber laser system operating on the zero-phonon line at 977 nm. An actively Q-switched master fiber oscillator delivers nanosecond pulses (FWHM 12-32 ns) at adjustable multiples of 10 kHz repetition rates that are further amplified in an ultralarge core photonic crystal fiber amplifier. At the highest available pumping level, a maximal average power of 78 W was obtained for 32 ns pulses at a repetition rate of 190 kHz, whereas the millijoule energy level was reached for 12 ns pulses at the lower repetition rate of 10 kHz.

High power ytterbium-doped rod-type three-level photonic crystal fiber laser.

In this paper, we investigate power scalability of ytterbium-doped ultra large core photonic crystal fiber laser operating on the zero-line transition. We first report on an 80 microm core diameter ytterbium-doped rod-type photonic crystal fiber laser emitting up to 94 W in continuous wave regime when operating at 977 nm, which is to our knowledge the highest output power ever achieved from a single-mode solid-state laser operating at this wavelength. Key parameters of ytterbium-doped three-level laser, such as transparency pump intensity, pump absorption saturation, and gain competition between three and four-level laser operation are then discussed in the particular context of high power fiber laser operating at 977 nm.