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It was shown that the spectral width of a nominally continuous wave Raman fiber laser (RFL) output becomes narrower after propagation in normal dispersion (β2>0) fiber [1]. This feature, attributed to Inverse Four-Wave Mixing (IFWM), was especially pronounced when the RFL output had a double-peak spectral shape caused by efficient FWM inside the cavity [2]. This spectrum was transformed into a...
Optical rectification of ultrashort laser pulses in electro-optic crystals is an established technique of terahertz generation. In this technique, the pump optical pulse produces a nonlinear polarization that moves with the group velocity of the optical pulse and acts as a source of terahertz radiation. The up-to-date generation schemes based on this principle utilize both the standard collinear phase...
In the past years rare-earth-doped fiber lasers have emerged as attractive and power scalable solid-state laser concept due to the outstanding thermo-optical properties of an actively doped fiber. The large ratio of surface to active volume of such a fiber ensures excellent heat dissipation, furthermore the beam quality is defined by the refractive index profile of the active core and is therefore...
Traditional lasers are composed by three basic elements: an amplifying medium, an external pumping setup, and an optical cavity that confines and shapes the emitted light in well-determined modes and directions. However, several modern approaches are extending this traditional laser paradigm into new avenues. Cavity-free stimulated emission of radiation has been widely studied in random lasers (RLs)...
We present a numerical study of the nonlinear dynamics of a population of coupled semiconductor lasers with saturable absorber operating in the excitable regime [1] and described by a set of coupled Yamada models [2]. In particular we have investigated the self-organized synchronization process taking place spontaneously among the lasers, showing significant correlations between the spike-like pulses...
Mid-infrared coherent sources at 3–4 μm have a wide variety of applications that include, but are not limited to gas sensing, material processing and production control. The MgO-doped periodically poled lithium niobate (MgO:PPLN) crystal is a well-known nonlinear element for quasi-phase-matched optical parametric oscillators (OPOs) typically pumped by 1-μm laser radiation [1]. However, strong multi-phonon...
Stimulated Raman scattering presents one of important trends in nonlinear optics enabling to generate Stokes-shifted radiation at frequencies that are not readily available from solid state lasers. This method is suitable also because the phase matching fulfilment isn't required. To get stable and efficient Raman generation of picosecond and even femtosecond ultra-short Stokes pulses, the method of...
Satellite-based laser-based remote sensing (lidar) of the atmosphere can be used for meteorology, atmospheric chemistry and climate change but requires high energy (100mJ-class) lasers with precision wavelength control. A high energy Alexandrite laser source is an interesting alternative to Nd:YAG in future Earth Observation missions with its added scientific benefit of broad wavelength tunability...
Many trivalent rare earth ions, such as praseodymium (Pr), samarium (Sm), terbium (Tb) and dysprosium (Dy), have radiative transitions in the visible wavelength region, and those visible lasers have been reported [1]. Especially, Pr3+-doped lasers are successful so far as one of the most efficient approaches for visible lasing thanks to the development of indium gallium nitride (InGaN) diode lasers.
Optical frequency combs provide an equidistant grid of optical frequency components, enabling a wide array of diverse and new technologies [1]. One such application is photonic microwave generation where optical frequency combs provide unprecedented low-noise performance via optical frequency division [2]. Although providing excellent performance, it comes at the expense of size and complexity. In...
Mechanisms of rogue waves (RWs) emergence have been extensively studied in fiber lasers with nonlinearly driven cavities [1], Raman fiber amplifiers and lasers [2], and fiber lasers via modulation of the pump [3]. Previously, it has been found that RWs can be emerged because of soliton-soliton interaction through the overlapping of their tails or soliton-dispersive wave interaction. The result of...
Dual order bidirectional Raman amplification are preferred over first order counterpart due to their lower signal power variation (SPV) and consequently superior optical signal to noise ratio (OSNR) performance [1]. These benefits are counteracted by the disadvantage of relative intensity noise (RIN) transfer from forward pumps to signal [1, 2]. In this work, we demonstrate a forward pumping scheme...
Inducing and controlling lasing in the open air is an intriguing challenge. Several recent experiments on laser filamentation in air have demonstrated generation of population inversion and lasing at the 391 nm and 428 nm lines in the nitrogen molecular ion [1-8], corresponding to transitions between the ground vibrational state of the second excited electronic state, B2Σ+u, and the ground and first...
Raman fiber lasers (RFLs) are treated as perspective laser sources in spectral bands which are not available from rare-earth (RE) doped fiber lasers. Raman lasing can be easily obtained from 1.1 to 2 μm in single-mode fibers that are core-pumped by RE-doped fiber lasers generating single transverse mode. However, the RFL generation below 1, Mm is difficult because of a lack of suitable high-power...
High power linearly polarized narrow linewidth light source above the wavelength of 1600 nm are very attractive for several applications such as pump source for Cr:ZnS[1], Tm:Re2O3 (Re=Sc. Lu or Y) or nonlinear frequency conversion. Er (or Er:Yb)fibers are most popular gain media around the wavelength of 1.55 μm, though, there are few reports of Er fiber lasers above 1600 nm satisfying aforementioned...
Hollow optical fibres offer a unique photonic platform by confining light in a void which may be filled with a vacuum or a gas at low or high pressure. The lack of substantial overlap of the light with the solid parts of the fibre surrounding the hollow core also increases the fibre damage threshold and reduces the attenuation in regions where the glass is absorbing strongly. For the current generation...
Optical parametric chirped pulse amplification (OPCPA) is widely recognized as a key technique for producing intense few-cycle light pulses for attosecond science [1]. Owing to the continuous improvement of diode-pumped solid state (DPSS) lasers, the OPCPA technique is becoming ever more attractive as combining DPSS laser pump sources and OPCPA enables simultaneous scaling of peak and average power...
High-peak-power longwave OPAs operating above the wavelength of 5μm [1] require high-energy picosecond pump pulses >2 μm. These can be generated directly in laser amplifiers, e.g. Ho-doped [1, 2] or via cascaded OPAs [3]. Burst-mode pump lasers offer great advantages over single-pulse amplifiers because they help overcoming the challenges of chirped-pulse as well as direct picosecond pulse amplifiers...
We demonstrate that a novel family of miniaturized deformed helix ferroelectric liquid crystal cells that has recently been developed in the context of distributed optical sensing networks can also be used to realize fully monolithic, actively Q-switched waveguide lasers as well as actively mode-locked all-fiber lasers. Those cells enable the development of pulsed laser sources with the same level...
Owing to their high beam quality and enormous power scalability, Yb-doped fiber lasers and amplifiers are currently employed for many scientific and industrial applications. However, photodarkening losses and high operating temperatures can limit their performance or even destroy the laser itself. PD loss reduces the laser efficiency during run-time of fiber laser. Technically, this problem can be...
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