Fabio Di Teodoro

Multimegawatt peak-power, single-transverse-mode operation of a 100μm core diameter, Yb-doped rodlike photonic crystal fiber amplifier

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.

1-mJ energy, 1-MW peak-power, 10-W average-power, spectrally narrow, diffraction-limited pulses from a photonic-crystal fiber amplifier.

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.

Diffraction-limited, 300-kW peak-power pulses from a coiled multimode fiber amplifier

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.

1.1 MW peak-power, 7 W average-power, high-spectral-brightness, diffraction-limited pulses from a photonic crystal fiber amplifier

We report a large-core, Yb-doped photonic crystal fiber amplifier generating diffraction-limited (M2 = 1.04), approximately 0.45 ns, approximately 8 GHz linewidth pulses with energies of 540 microJ, peak power in excess of 1.1 MW, and average power of approximately 7.2 W at a repetition rate of 13.4 kHz. The pulse peak spectral brightness exceeds 10 kW/(sr Hz cm2) and is the highest generated by a fiber source, to our knowledge.

Efficient second, third, fourth, and fifth harmonic generation of a Yb-doped fiber amplifier

We report generation of the second, third, fourth, and fifth harmonics of the output of a Yb-doped fiber amplifier seeded by a passively Q-switched Nd:YAG microchip laser. We obtained high conversion efficiencies using a simple optical arrangement and critically phase-matched nonlinear crystals. Starting with 320 mW of average power at 1064 nm (86 μJ per pulse at a 3.7 kHz repetition rate), we generated 160 mW at 532 nm, 38 mW at 355 nm, 69 mW at 266 nm, and 18 mW at 213 nm. The experimental results are in excellent agreement with calculations.

High-gain Er-doped fiber amplifier generating eye-safe MW peak-power, mJ-energy pulses

We report on a large-core, Er-doped fiber amplifier that generates pulses of approximately 1.1 ns duration and maximum pulse energy/peak power approximately 1.4 mJ/1.2 MW, at 1567 nm wavelength, while concurrently providing optical gain in excess of 25 dB, in a multi-mode output beam (M(2) approximately 8.5).

Multistage Yb-doped fiber amplifier generating megawatt peak-power, subnanosecond pulses.

A Q-switched microchip laser generating 1064 nm wavelength, subnanosecond pulses at a 13.4 kHz repetition rate was used to seed a dual-stage amplifier featuring a 40 microm core Yb-doped photonic-crystal fiber (PCF) as the power amplifier. From this source, we obtained diffraction-limited (M2 = 1.05), approximately 450 ps pulses of energy > 0.7 mJ, peak power in excess of 1.5 MW, and an average power of approximately 9.5 W. By further amplifying the PCF output in a multimode 140 microm core Yb-doped fiber, we generated a peak power in excess of 4.5 MW, the highest obtained in a fiber source to our knowledge.

Watt-level, high-repetition-rate, mid-infrared pulses generated by wavelength conversion of an eye-safe fiber source

We report on a mid-infrared (mid-IR) source consisting of an approximately 10 W average-power, linearly polarized 1.54 microm wavelength pulsed fiber source pumping an optical parametric oscillator. From this source, we obtained average power in excess of 1 W in the 3.8-4.0 microm wavelength range at a pulse repetition frequency of 100 kHz. With a slightly different setup, we also achieved an average power of 0.25 W at 4.5 microm wavelength. To our knowledge, these values represent the highest mid-IR power obtained through wavelength conversion of an eye-safe fiber source.

Harmonic Generation of an Yb-Doped Photonic-Crystal Fiber Amplifier to Obtain 1ns Pulses of 410, 160, and 190kW Peak-Power at 531, 354, and 265nm Wavelength

By frequency doubling, tripling, and quadrupling 1ns, ~10kHz-repetition-rate pulses from a 1062nm-wavelength Yb-doped photonic crystal fiber amplifier, we obtained pulse peak/average powers of 410kW/4W at 531nm, 160kW/1.5W at 354nm, and 190kW/1.8W at 265.5nm.

Multi-MW peak power single-transverse mode operation of a 100 micron core diameter, Yb-doped photonic crystal rod amplifier

We developed a gain-staged master-oscillator/power-amplifier source featuring an Yb-doped, 100&mgr;m-core rod-like photonic crystal fiber (PCF) as the final amplifier. From this PCF, we obtained 1ns pulses of energy in excess of 4.3 mJ, peak/average power ~ 4.5 MW / 42W, and spectral width ~20 GHz. The PCF emitted a near-Gaussian, single-transversemode beam of M2~1.3.