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In this article, we experimentally investigate the dynamics of dissipative soliton resonance (DSR) square pulses in different all-anomalous passively mode-locked double-clad Er:Yb fiber laser setups. In the figure-of-eight configuration, the aim of employing an amplifier in each loop is to control the output pulse's amplitude and width, which depend on the pumping power. At a maximum total pumping power of 4.7 W and a fundamental frequency of 133 kHz, 10 µJ DSR square pulses with a signal-to-noise ratio of 60 dB, are generated without observing any wave-breaking. In the fiber ring configuration, by fixing the pumping power to 1.18 W and carefully adjusting the polarization controllers, we obtain a DSR square pulse that can be split in a series of equally spaced smaller square pulses up to the 4th harmonic order at a fundamental frequency of 672 kHz.

We have proposed an exhaustive experimental study of dissipative soliton resonance in a double clad Er:Yb co-doped dual amplifier passively mode-locked figure-of-eight fiber laser. By adjusting the pumping powers of the amplifiers, both the amplitude and width of the output square-wave pulse can be tuned continuously. Moreover, some other key parameters such as the net cavity dispersion and the coupling ratio between the two loops of the cavity have been studied.

We present a widely adjustable high energy square pulse laser operating in DSR in a passively mode-locked F8L using dual Er:Yb co-doped double clad amplifiers. By manually controlling the power of each amplifier, the pulse width can be varied in a range of 360 ns without generating multi-pulsing instabilities. To ensure that DSR would dominate the modelocking mechanism, we use a 1.5 km standard single-mode fiber in the cavity. At a maximum pumping power, the laser generated square pulses with 416 ns duration and an average output power of about 1.33 W with a repetition frequency of 133 KHz corresponding to a record pulse energy of 10 μJ.

We describe the implementation of echo dynamic light scattering in a cross-correlation detection scheme, which enables the study of slow dynamics in moderately turbid colloidal systems by adapting a commercial light scattering device. Our setup combines a 3D cross-correlation detection scheme (3DDLS), which allows for suppression of multiple scattering, with the speckle echo technique for dynamic light scattering. The recorded cross-correlation echoes provide precise ensemble-averaged results that appropriately describe sample dynamics of ergodic and non-ergodic colloidal systems of different turbidities. Additionally, the high mechanical stability achieved in our setup makes possible an absolute estimation of the scattering intensity correlation function (ICF) directly from the height of echoes, thus making unnecessary any correction for imperfect rotation of the sample or of any ad hoc assumption regarding the correspondence between the absolute values of echo height and ICF. Furthermore, we find that zeroth-order echo height represents the coherence factor of the 3DDLS experiment.

Based on the dissipative soliton resonance occurring in highly anomalous dispersion regime, we have demonstrated the emission of highly energetic square-wave pulses from the Er:Yb doped double clad fiber laser passively mode-locked through nonlinear polarization evolution. In contrast with the classical soliton regime, when the pumping power increases the pulse broadens and its energy increases, both linearly. Experimental results exhibit a stable mode-locking with single pulse energy as high as 2.27 µJ, a pulse duration of about 200 ns and an average output power of 850 mW.

International audience; We have experimentally demonstrated square pulses emission from a co-doped Er:Yb double-clad fiber laser operating in anomalous dispersion DSR regime using the nonlinear polarization evolution technique. Stable mode-locked pulses have a repetition rate of 373 kHz with 2.27 µJ energy per pulse under a pumping power of 30 W in cavity. With the increase of pump power, both the duration and the energy of the output square pulses broaden. The experimental results demonstrate that the passively mode-locked fiber laser operating in the anomalous regime can also realize a high-energy pulse, which is different from the conventional low-energy soliton pulse.

International audience; We demonstrate experimentally a double-clad Er:Yb co-doped dual amplifier passive mode-locked figure-of-eight fiber laser that generates high energy, width, and amplitude tunable dissipative soliton resonance square pulses. In our laser system, each loop contains an amplifier that controls a characteristic of the output pulse. The amplitude and width of the output beam can be controlled continuously but, dependently, according to the pump power of each amplifier. The pulse width can be tuned in a range of almost 360ns while the peak power varies from 8 to 120W. On maximum possible pumping from both sides without having a pulse break, we report square pulses with 10μJ energy per pulse with a signal-to-noise ratio of 60dB.

International audience; We demonstrate the possibility of generating wave-breaking-free optical pulses from a mode-locked fiber ring laser coupled to a long passive resonator. By adjusting the delay line length to match the temporal separation of two consecutive spiking pulses, we have successfully obtained large stable pulses in the microsecond range for any available pump power. Our experimental results demonstrate a new method for energy scaling in passively mode-locked fiber lasers.

International audience; We investigate experimentally the operational boundaries of dissipative soliton resonance in a double-clad Er:Yb co-doped dual amplifier passively mode-locked figure-of-eight fiber laser. While mode-locking with a nonlinear amplifying loop mirror, we present an exhaustive series of experiments in order to optimize the pulse energy and pulse width tunability. In addition to the pumping power of the amplifiers, several key experimental parameters have been identified such as the net cavity dispersion, the coupling ratio between the two loops of the cavity and the exact position of the long fiber coils. Under optimized conditions, the laser delivers square pulses with an energy varying between 8.5 and 10.1 μJ while the pulse width ranges from 84-416 ns.

The $ \beta^{{+}}_{}$ /EC decay of 185Tl was studied at the ISOLDE facility, the $ \gamma$ -rays belonging to 185Hg have been identified and a partial low-spin level scheme of 185Hg has been built. The decay of 185m+gHg was studied at the ISOCELE facility. Conversion electron lines of very low-energy transitions were observed for the first time. Electron data have been obtained for four transitions in 185Au and two transitions in 185Hg . From the analysis performed using an internal energy calibration procedure the energy location of the 185mHg has been determined to be $ E_{IS}= 103.7(4)$ keV. This $ E_{IS}$ value is consistent with that determined independently, $ E_{IS}=94(13)$ keV, using 185m+gHg $ \alpha$ -decay data from literature. New $ \alpha$ particles emitted from 189m+gPb have been detected and their origins determined by in-source laser spectroscopy at the ISOLDE facility. $ \alpha$ - $ \gamma$ coincidence results have served to locate the $ 13/2^{+}$ isomeric state of 189Pb at $ E_{IS}=40(4)$ keV. This latter $ E_{IS}$ value added to $ \alpha$ -decay data from literature have allowed the energy location of the $ 13/2^{+}$ isomeric states of 193Po and 197Rn at 95(7)keV and 194(12)keV, respectively. The nuclear structure of the isomeric and ground states in the nuclei of the three $ \alpha$ -emitter chains starting with 195m+g, 197m+g, 199m+gRn are discussed.

Low-spin states of 186 Ir populated through the β + /EC decay of 186 Pt nuclei were studied using mass-separated sources and γ-ray and e − spectroscopic techniques. A completely new level scheme of 186 Ir is established. It is shown that the 2 − isomeric state is located at an energy less than 1.5 keV above the 5 + ground state. A very low-energy transition from the 2 − isomer to the 5 + ground state has to exist in order to explain the data, and its relative intensity has been estimated to be around 25% of the total decay of the 2 − state. Most of the experimental levels are interpreted within the two-quasiparticle-plus-rotor model.

The detection of conversion electrons of short‐lived isotopes at ISOCELE has been extended to very low‐energy: a special tape‐transport system has been built which allows the slowing down of the incoming radioactive ions and the acceleration of the electrons detected on photographic film in a flat magnetic spectrograph. Results have been acquired for the decay of mercury with A=185, 186, 187, 189, 191, and of platinum with A=184, and 186. As examples the location of isomeric states deduced from our measurements are given to illustrate the power of high‐resolution electron detection.