We demonstrate the first large-core Er: ZBLAN fiber-based chirped-pulse amplification system operating at ∼2.79 µm. Single-mode amplification in a coiled 46 µm-core, ∼0.064 NA Er:ZBLAN fiber delivers up to ∼144 µJ of stretched femtosecond pulses (∼1.5 ns) at a 5.5 kHz repetition rate. After diffraction-grating compression, ∼70 µJ pulses with a duration of ∼525 fs are obtained. This represents what is believed to be a new record pulse energy for femtosecond-duration Er: ZBLAN fiber lasers, exceeding previous results by nearly two orders of magnitude. The performance is enabled by a diffraction-grating based CPA architecture combined with large-mode-area fiber operating robustly in a single transverse mode.

We demonstrate high-energy nanosecond pulse amplification at ∼2.78 µm in a robust single transverse mode from a coiled large core low-numerical aperture (NA) Er:ZBLAN fiber amplifier. The highest energy achieved is 1.01 mJ from a 46 µm core Er:ZBLAN fiber, seeded with a preamplifier in a single-mode fiber 30 ns long pulses from a ring-cavity Q-switched Er:ZBLAN fiber laser. Near-diffraction-limited beams with M2 = 1.09 were obtained using coiling-induced high-order mode filtering in a custom-fabricated 46 µm diameter and ∼0.064 NA core fiber. This constitutes, to the best of our knowledge, the highest-energy nanosecond duration pulses in a single transverse mode from an Er:ZBLAN fiber laser system to date.

We report high energy nanosecond pulse amplification at 2.78µm in a robust single mode. Up to ~1mJ were obtained with 30ns pulses after single-mode amplification in a coiled 46µm and ~0.064NA core Er: ZBLAN fiber.

We report development of the first large-core fiber CPA system operating in Mid-IR. Up to ~100µJ were obtained with ~500ps stretched femtosecond pulses after single-mode amplification in a coiled 46µm and ~0.07NA core Er:ZBLAN fiber.

We present an ultrafast long-wave infrared (LWIR) source driven by a mid-infrared fluoride fiber laser. It is based on a mode-locked Er:ZBLAN fiber oscillator and a nonlinear amplifier operating at 48 MHz. The amplified soliton pulses at ∼2.9 µm are shifted to ∼4 µm via the soliton self-frequency shifting process in an InF3 fiber. LWIR pulses with an average power of 1.25-mW centered at 11 µm with a spectral bandwidth of ∼1.3 µm are produced through difference-frequency generation (DFG) of the amplified soliton and its frequency-shifted replica in a ZnGeP2 crystal. Soliton-effect fluoride fiber sources operating in the mid-infrared for driving DFG conversion to LWIR enable higher pulse energies than with near-infrared sources, while maintaining relative simplicity and compactness, relevant for spectroscopy and other applications in LWIR.

We demonstrate high energy pulses in a single transverse mode from 50µm and 30µm core Er:ZBLAN fibers in mid-IR at ~2.8µm. 100ns pulses with up 450µJ have been achieved at kHz repetition rates.

We demonstrate single transverse mode and high energy nanosecond pulse amplification at ∼2.8-µm using large core Er:ZBLAN fibers. The highest energies achieved are 0.75mJ from a 50 µm core, and 420µJ from a 30 µm core fibers respectively, seeded with 95 ns long pulses generated by a ring-cavity Q-switched Er:ZBLAN fiber laser. Nearly diffraction-limited beams with M2 = 1.2-1.3 were obtained using a single-mode excitation technique of multi-mode core fibers. Achieved pulse energies exceed by approximately an order of magnitude the previously reported highest pulse energies in a single transverse mode from a fiber laser or amplifier at these mid-IR wavelengths.

We report demonstration of a new spectrally-controllable device, based on a sequence of linear polarizers and birefringent plates, which allows to accurately and adjustably tailor its spectral filtering properties for achieving complete gain-narrowing compensation over ~30nm of signal bandwidth in an Yb-doped fiber system with the total gain reaching 150dB. The experimental demonstration was performed in a regenerative Yb-fiber amplifier system with controllable number of passes, allowing to characterize both signal spectral-narrowing, and as well as spectral compensation at varying levels of achieved total gain. This result opens a pathway towards 100fs duration multi-mJ pulses from fiber CPSA systems.

In this paper, we report a high power and compact mid-IR ultrafast laser system consisting of an Er:ZBLAN fiber-based mode-locked oscillator and a nonlinear amplifier. The mode-locked pulses are amplified and simultaneously nonlinearly compressed to sub-100 fs, without using any external pulse compressor or dispersion-managing stretcher. The output pulses have ∼85 fs pulse durations at ∼2.85 µm, with an average power of up to 2.4 W, and pulse energies of >40 nJ. This constitutes the highest average power sub-100fs duration pulses generated from a mid-IR fiber laser system to date.

Ultrashort mid-IR pulse train with 95 fs pulse width, 37.4 nJ pulse energy and 1.8 W average power was generated at ~2.85 µm from a simple Er:ZrF4 fiber nonlinear amplifier seeded by a mode-locked oscillator.

We explored generation of high-energy nanosecond short pulses in the mid-IR wavelength range using 30–70-µm-core Er:ZBLAN fiber amplifiers. The highest energies achieved were ∼ 0.7 m J at 2.72 µm in 11.5-ns-long pulses, with the corresponding peak power of 60.3 kW, obtained with a 70-µm-diameter core fiber amplifier pumped at 976 nm and seeded by a K T i O A s O 4 -based optical parametric oscillator/optical parametric amplifier system. To the best of our knowledge, these pulse energies are the highest achieved to date from mid-IR fiber lasers at longer than 2-µm wavelengths with nanosecond pulses. The achieved highest pulse energies were limited by the surface damage of unprotected fiber output facets.

We explored generation of high-energy nanosecond short pulses in the mid-IR wavelength range using 30-70-µm-core Er:ZBLAN fiber amplifiers. The highest energies achieved were ∼0.7mJ at 2.72 µm in 11.5-ns-long pulses, with the corresponding peak power of 60.3 kW, obtained with a 70-µm-diameter core fiber amplifier pumped at 976 nm and seeded by a KTiOAsO4-based optical parametric oscillator/optical parametric amplifier system. To the best of our knowledge, these pulse energies are the highest achieved to date from mid-IR fiber lasers at longer than 2-µm wavelengths with nanosecond pulses. The achieved highest pulse energies were limited by the surface damage of unprotected fiber output facets.

Pulsed amplification at 2.7µm in Er:ZBLAN LMA fibers was explored demonstrating up to 194µJ in 9.7ns, the highest short-pulse energies from these mid-IR fibers. We also measured fiber damage threshold and 650µJ of stored energy. © 2019 The Author(s)

Pulsed amplification at 2.7 mu m in Er:ZBLAN LMA fibers was explored demonstrating up to 194 mu J in 9.7ns, the highest short-pulse energies from these mid-IR fibers. We also measured fiber damage threshold and 650 mu J of stored energy. (C) 2019 The Author(s)

We demonstrate 667µJ and 11.5ns pulses at 2.72μm from an LMA Er:ZBLAN fiber amplifier with 70µm core. This represents the highest energy and peak power ever obtained in mid-IR with a fiber laser source.

We experimentally demonstrate a novel broadband dispersion compensator designed for ~50fs-150fs pulses that uses controlled optical aberrations to compensate third and fourth order dispersion accumulated in ~50m long fiber path of a fiber CPA system.

Mode-locked oscillator pulse phase is stabilized and locked to an external cavity in a novel way by using a phase-sensitive peak power response of the Gires-Tournois interferometer, which enables significant increase in phase-measurement sensitivity.

We show that the relative intensity noise (RIN) of nonlinear-amplifying-loop-mirror-based fiber lasers can be dramatically reduced to only 0.0062% (rms) [10 Hz – 1 MHz] by the combined use of intra- and extra-cavity optical filtering.