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We demonstrated a narrow pulse-width long-wave infrared ZnGeP2 (ZGP) optical parametric oscillator (OPO) pumped by a 2.1 μm Ho:YAG master oscillator power-amplifier (MOPA). By short-cavity structure, a minimum pulse width of ∼12 ns was achieved at 1kHz, 2kHz and 3kHz in Ho:YAG oscillator. By employing a three-stage amplifier, a maximum average output power of 73.1 W with pulse width of ∼17 ns at the pulse repetition frequency of 3 kHz was obtained. Then a ZGP OPO pumped by the Ho:YAG MOPA was demonstrated. The maximum average output powers of 5.48 W at 8.2 μm and 22.4 W at 2.8 μm were obtained, corresponding to the pulse width of

We demonstrated a mode-controllable fiber laser system with output power of 1.4 kW level. The system consists of a kilowatt-scale master oscillator power amplifier and an active feedback control system based on the stochastic parallel-gradient descent algorithm. We can convert the LP01 and LP11 modes by performing an extremum search for power in the bucket of the output beam. Under the same pump power, we obtain the mode conversion of LP11 to LP01, and the efficiency is as high as 99.5%. The maximum output power of LP11 and LP01 mode are 1396 W and 1389 W, respectively, with corresponding slope efficiencies of 85.8% and 84.1%.

We demonstrate a pulse-duration tunable Tm3+-doped pulsed all-fiber master oscillator power amplifier (MOPA) operating at a central wavelength of 1908 nm. By using acousto-optic(AO) external modula...

A high power Ho:YAP laser in-band pumped by a home-constructed Tm doped all fiber master oscillator power amplifier (MOPA) is reported. The optically polished and uncoated Ho:YAP laser yielded over 107 W of output power at ~2117.1 nm with 215.4 W of absorbed pump power, corresponding to a slope efficiency of 50.6% with respect to the absorbed pump power. The beam quality M2 parameter was measured at 80 W of output power to be ~3.2 and ~2.6 in x- and y-directions, respectively.

Poster; International audience; We describe the design and characterization of a master oscillator – power amplifier laser system operating under µs-pulse regime at 828 nm, with a view to its integration in an airborne lidar for tropospheric water-vapor measurements. The output energy reaches 6.2 µJ per pulse.

In this paper, we present experimental studies on newly developed multiplexed chirped tilted fiber Bragg gratings (MCTFBGs) for stimulated Raman scattering (SRS) suppression for high-power fiber laser systems. The MCTFBG device is composed of five continuous segments of chirped tilted fiber Bragg gratings (CTFBGs), which are inscribed into the large-mode-area (LMA, 25/400μm) fibers. The SRS suppression capability of the MCTFBG device has been successfully demonstrated with a master oscillator power amplification (MOPA) fiber laser system at the output level of 3.4 KW. The experimental observation thus indicates the MCTFBG’s excellent SRS suppression capability at a very high power level (∼15 dB under >3 kW) and high thermal handling capacity (∼1.48℃/kw). Our work thus provides a key development of essential fiber grating components that can effectively suppress the SRS suppression at a very high power level.

A high-power all-fiber supercontinuum (SC) source in a highly germania-doped fiber (GDF) pumped by a picosecond thulium-doped master oscillator power amplifier (MOPA) system is presented. By further optimizing the length of the GDF, the long-wavelength edge of the wideband flat SC can be broadened to 3 μm. The flat SC has an average output power of 11.62 W and a 3 dB bandwidth of 750 nm. The power proportion beyond 2400 nm is as high as 55.3%. To our knowledge, this SC average output power is the highest from a highly GDF.

Characteristics of an efficient spectral beam combination of two dye laser beams with wavelength difference of less than 10 nm are presented. Two dye laser oscillator beams were spatially and temporally combined with reduced losses before their co-amplification in a common power amplifier. Yellow and green beams of 9 kHz (pulse repetition rate) copper vapour laser (CVL) Master Oscillator Power Amplifier (MOPA) Chain were utilised to pump Rh 101 dye laser oscillators and DCM dye common amplifier respectively. The characteristics of green beam pumped DCM dye common amplifier were studied at various pump power and input power ratios. Combination losses for this configuration were 40% relative to individually amplified configuration. Input–output characteristics of the common amplifier were determined at various input power ratios. Composite dual wavelength dye laser beam having total power of 7.35W at 38.4 W pump power with extraction efficiency 16.5% was demonstrated.

We demonstrated a master oscillator power amplifier (MOPA) based on Yb:KGW and Yb:YAG crystals at 1 MHz repetition rate without chirped pulse amplification (CPA) technique. The Yb:KGW oscillator delivered 1.28 W, 1.87 ps pulses with a repetition rate of 45 MHz. After an acousto-optic modulator (AOM) as the pulse picker, the repetition rate was reduced to 1 MHz. Subsequently, the seed was sent to Yb:YAG amplifiers and boosted to an average power of 8.2 W with a pulse duration of 4.66 ps, corresponding to a pulse energy of 8.2 μ J and a peak power of 1.76 MW.

An integrated zigzag laser diode amplifier, with each segment (zigzag) consisting of three sections, is considered. The operation of this amplifier is analysed. It is shown that the presence of three sections with independent pump currents makes it possible to combine coherently all amplifier output beams. The first two sections in this configuration play the role of a phase shifter, and the third serves as a power amplifier. The influence of fluctuations of the output radiation phase in each segment on the resulting brightness of total output beam of the entire amplifier is investigated.

A high-peak-power, high-repetition-rate compact pulse burst 1064 nm laser from a master oscillator power amplifier is presented. The maximum pulse burst energy reaches 409.4 mJ with a pulse number of 86 and a single pulse energy of 4.8 mJ in a duration of 1 ms. A peak power of 2.5 MW is obtained in the pulse burst laser with a pulse width of 2.0 ns. The pulse burst laser has a good amplitude stability with a variation coefficient of 5.0%.

We report on mid-IR Fe:ZnSe master oscillator power amplifier (MOPA) laser system operating at room temperature (RT) pumped by a radiation of mechanically Q-switched Er:YAG laser operating at 2.94 m, at 3Hz repetition rate. The maximum output energy was as high as 250mJ in ~250 ns pulses. The RT gain-switched Fe:ZnSe master oscillator demonstrated tunability over 3.60-5.15 µm spectral range with a maximum output energy of ~3 mJ. The output energies of 12 (8), 34 (25) and 60 (48) mJ were demonstrated at 4.4 (4.1) µm in the 1st, 2nd and 3rd stages of amplifier, respectively, with a total pump energy of 200 mJ.

Circadian rhythms are 24-h oscillations driven by a hypothalamic master oscillator that entrains peripheral clocks in almost all cells, tissues and organs. Circadian misalignment, triggered by industrialization and modern lifestyles, has been linked to several pathological conditions, with possible impairment of the quality or even the very existence of life. Living organisms are continuously exposed to air pollutants, and among them, ozone or particulate matters (PMs) are considered to be among the most toxic to human health. In particular, exposure to environmental stressors may result not only in pulmonary and cardiovascular diseases, but, as it has been demonstrated in the last two decades, the skin can also be affected by pollution. In this context, we hypothesize that chronodistruption can exacerbate cell vulnerability to exogenous damaging agents, and we suggest a possible common mechanism of action in deregulation of the homeostasis of the pulmonary, cardiovascular and cutaneous tissues and in its involvement in the development of pathological conditions.

10 W level 90 ps MOPA laser with pulse repetition rate up to 700 kHz was developed. Passively Q-switched Nd:YVO 4 microchip 1064 nm laser was used as a master oscillator. Double-rod double-end-pumping configuration of two-pass Nd:YAG ring power amplifier was used to achieve high gain with efficient energy extraction. High quality laser beam with M2

We present a concept of a novel redundancy solution for the master oscillator of the European-XFEL facility. The solution implements automated switching between identical copies of the reference signal generation chains. The main difference from prior solutions is the ability to maintain a continuous reference signal also in the event of switching, e.g. caused by a failure in the system.

We demonstrate that the combination of Ytterbium doped-fiber and bulk crystals amplifiers, in a Master Oscillator Power Amplifier configuration (MOPA) allows obtaining 3.6 mJ, 15 ns, single-frequency pulses and 5 kHz repetition rate.

We report on room temperature Fe:ZnSe MOPA system tunable over 3.6-5.2 µm pumped by radiation of Q-switched 2.94 µm Er:YAG laser. The maximum output energy was measured to be 60mJ under 200mJ of pump energy.

A stable multi-octave supercontinuum (SC) is generated in polarization-maintaining ZBLAN fiber using pulses from a master oscillator fiber amplifier. The SC is characterized using a sum-frequency generation cross-correlation frequency-resolved optical gating (SFG-XFROG).

International audience; 18 Heart rate and blood pressure oscillate in phase with respiratory activity. A component of 19 these oscillations is generated centrally, with respiratory neurons entraining the activity of 20 pre-sympathetic and parasympathetic cardiovascular neurons. Using a combination of 21 optogenetic inhibition and excitation in vivo and in situ in rats, as well as neuronal tracing, we 22 demonstrate that preBötzinger Complex (preBötC) neurons, which form the kernel for 23 inspiratory rhythm generation, directly modulate cardiovascular activity. Specifically, 24 inhibitory preBötC neurons modulate cardiac parasympathetic neuron activity whilst 25 excitatory preBötC neurons modulate sympathetic vasomotor neuron activity, generating 26 heart rate and blood pressure oscillations in phase with respiration. Our data reveal yet more 27 functions entrained to the activity of the preBötC, with a role in generating cardiorespiratory 28 oscillations. The findings have implications for cardiovascular pathologies, such as 29 hypertension and heart failure, where respiratory entrainment of heart rate is diminished and 30 respiratory entrainment of blood pressure exaggerated. 31 32

We demonstrated a cryogenically cooled Tm:Y2O3 master oscillator emitting around 1932.5 nm, which was tuned from 10 to 1000 Hz. Maximum pulse energy of 1.8 mJ (10 Hz) was achieved with 32 ns pulse duration.

Laser light in the yellow–green spectral range has to rely on frequency conversion as suitable direct emitting laser diodes are not available yet. With the help of newly developed and highly brilliant laser diodes, we are able to present a miniaturized laser module that emits laser light with an output power of more than 1.6 W at a wavelength of 576 nm. We achieved this by designing a small and compact module with a hybrid-integrated master oscillator power amplifier (MOPA) setup emitting at 1152 nm. For the second-harmonic generation of the laser light of the MOPA a periodically poled 42-mm-long volume LiNbO3 crystal is integrated. In this letter, we present the design and the electro-optical characteristics of this module.

A QCW LD pumped linearly polarized Nd3+:YAG/V3+:YAG laser operating at 1444 nm with high peak power of 62 kW is demonstated for the first time. The polarization extinction ratio of the 1444 nm output beam was higher than 1000:1 and the highest second-harmonic generation efficiency at 722 nm was 62.8%. A compact high-peak-power polarized Nd:YAG laser can be used as the master oscillator for a high energy system. In particular, a 722 nm laser is a viable source for biomedical applications such as photoacoustic imaging, oximetry, and tattoo removal.

A 10 W level master oscillator power amplifier (MOPA) laser with pulse repetition rate up to 1 MHz and 75–95 ps pulse duration was developed based on a passively Q -switched N d : Y V O 4 microchip 1064 nm laser as a master oscillator. A double-rod double-end-pumping configuration of two-pass Nd:YAG ring power amplifier was used to achieve high gain, near-Fourier-transform-limited pulses, and laser beam quality factor M 2 = 1.27 along both the horizontal and vertical directions.