ABSTRACT
We present an all-fiber optical parametric chirped-pulse amplification integrated system delivering a single-mode polarized beam. The system makes use of a specifically designed solid-core photonic hybrid fiber (i.e., combining modified total internal reflection and photonic bandgap mechanisms) that ensures sufficient birefringence to maintain the signal polarization. Moreover, the fiber combines a large mode area to handle energetic pump pulses (without generating damage or unwanted nonlinear effects) and weak dispersion to generate parametric gain bands broad enough to amplify ultrashort pulses. An efficient parametric process allows for obtaining a very high gain (>45â dB) with an output pulse energy reaching µJ range at 1053 nm by using a single 5-m hybrid fiber amplifier.
ABSTRACT
We present the experimental investigation of timing jitter and relative intensity noise of a Mamyshev ring oscillator operating in the fundamental mode-lock regime. We find that both timing jitter and intensity noise spectra are correlated to the output optical power with noise increase close to the loss of the mode-locking. In addition, we have investigated the dependence of the spectral filters wavelength separation on both timing jitter and intensity noise showing a severe degradation with filters overlapping.
ABSTRACT
In this Letter, we present the first, to the best of our knowledge, experimental demonstration of high-order harmonic mode-locking of an all-fiber Mamyshev oscillator. The laser is entirely realized using standard step-index fiber. It delivers time-stable pulse trains with average powers reaching more than 100 mW at the fundamental mode-locked repetition rate (7.7 MHz) and 1.3 W at the 14th harmonic (107.8 MHz).
ABSTRACT
We experimentally demonstrate the amplification of chirped pulses in a fiber optical parametric chirped pulse amplifier up to 1 µJ. This high energy level originates from combined Raman and parametric processes in a specially designed solid core photonic bandgap fiber. Output pulses are recompressed up to 560 fs. These performances make this all-fiber system compatible with first stages of bulk amplification chains.
ABSTRACT
We report, through numerical simulations and experimental data, the first successful fabrication of a polarization maintaining single-mode fiber delivering a flat top intensity profile at 1.05 µm. A high quality flat mode was obtained and single-mode behavior was checked by shifting the injection and by S² imaging method. Numerical investigations were performed to show that it would be possible to increase further the 0.6x10â»4 experimental group birefringence.
ABSTRACT
We report on an all-fiber system delivering more than 100 µJ pulses with a top-hat beam output in the few nanoseconds regime at 10 kHz. The linearly polarized flattened beam is obtained thanks to a 3-mm-long single-mode microstructured fiber spliced to the amplifier's output.
ABSTRACT
We numerically and experimentally demonstrate ultra-broadband fiber optical parametric amplification in a microstructured fiber pumped by stretched short pulses. The chirped pump pulse induces a temporally spread spectral gain suitable for optical parametric chirped pulse amplification in fibers. Numerical simulation shows ~45 dB flat gain with more than 70 nm bandwidth, allowing sub-35 fs pulse amplification around 1 µm with reduced gain narrowing. This amplification principle is experimentally confirmed by measuring the instantaneous spectral gain band and related chirp.
ABSTRACT
A new strategy to obtain a single-mode fiber with a flattened intensity profile distribution is presented. It is based on the use of an OVD-made high index ring deposited on a silica rod having a refractive index slightly lower than the silica used for the microstructured cladding. Using this strategy, we realized the first single-mode fiber with a quasi-perfect top-hat intensity profile around 1 µm. Numerical studies clearly demonstrate the advantage of using a core index depression to insure the single-mode operation of the fiber at the working wavelength.
ABSTRACT
We demonstrate with realistic numerical simulations that fiber optical parametric chirped pulse amplification is able to amplify ultra-short optical pulses. Such amplifiers driven by two-pump waves can amplify pulse bandwidth twice as large as the one of a single pump configuration. We show that pulses as short as 50 fs can be directly amplified. In addition, we take benefit from the saturation regime to achieve spectral broadening which makes possible to reduce pulse duration down to 15 fs.
Subject(s)
Amplifiers, Electronic , Fiber Optic Technology/instrumentation , Lasers, Solid-State , Oscillometry/instrumentation , Equipment Design , Equipment Failure AnalysisABSTRACT
We present a versatile master-oscillator power amplifier system at 1053 nm in the few-nanoseconds regime meeting the high-level requirements of high-power laser facility front ends. Thanks to temporal shaping, more than 1.5 mJ pulse energy at 1 kHz with an excellent optical signal-to-noise ratio has been obtained in a single-mode 40 µm core flexible fiber.
ABSTRACT
Fiber-based optical-parametric chirped-pulse amplification is reported at 1µm in a microstructured fiber in the femtosecond regime. The signal has been highly stretched by an Öffner triplet and then amplified with an all-fiber, pulsed-pump, fiber optical-parametric amplifier. More than 30dB gain has been achieved over 8.3nm, and the amplified signal has been recompressed.
ABSTRACT
We experimentally demonstrate optical parametric chirped pulse amplification for the first time (to our knowledge) in a completely integrated all-fiber optical system. A single chirped fiber Bragg grating, achieving both the stretching and compression stages, is combined with a cw-pumped fiber optical parametric amplifier. As a proof of principle, we demonstrate the amplification of picosecond Fourier-transform-limited pulses at 1550nm.
ABSTRACT
We report on a single shot optical parametric chirped pulse amplifier designed to seed the Petawatt Aquitaine Laser on the Laser Integration Line facility multipetawatt high-energy laser. The scheme is based on a stretched signal pulse at 1053 nm amplified with 20% conversion efficiency by a monomode pump pulse at 527 nm. The homemade pump laser is able to deliver a single shot beam with a square flat top spatial profile and programmable temporal shape. A high-stability 150 mJ, 8 nm, and 4.5 ns stretched pulse is then obtained with an excellent quality spatially shaped beam.
ABSTRACT
Even if photochemical deposition of nearly all types of materials has been used for decades to pattern almost any kind of substrate for various applications (catalysis, chemical sensing, magnetic data storage, optoelectronics, spin-dependent electron transport, and solar cells), a rationalized description is still missing. This paper aims at fulfilling this lack by presenting a unified approach of the photodeposit growth initiated by a one-photon photochemical reaction. We experimentally investigate the robustness of growth scalings predicted for photochemical deposition driven by a continuous laser wave. Three types of one-photon photochemical reactions (photoexcitation of chromates, photodissociation of permanganates, and photocondensation of colloidal selenium) and three parameters (solvent p H variations, concentration in photoactive reagent, and influence of the exciting optical wavelength) were cross analyzed. In all the cases, including data taken from the literature, the same dynamic master behavior emerges from the data rescaling of measured deposit growth laws. The nice agreement observed between system-independent predictions and the whole data set strongly supports a universal description of the photodeposit growth whatever the photosensitive medium and the involved one-photon chemical reaction. Such an approach also points out the quantitative sorting of photochemical reactions in terms of deposition efficiency. This rationalization of the kinetics of photodeposition anticipates new methodologies to predict, design, and control substrate micropatterning for chemical, lithographic, and optoelectronic applications.
ABSTRACT
We present a degenerate noncollinear optical parametric chirped-pulse amplifier pumped by a high-energy, diode-pumped Nd:Glass regenerative amplifier delivering monomode pulses at 527 nm. The spatial mode shaping of the pump pulses is achieved with a diffractive laser cavity element, and temporal pulse shaping makes use of an electro-optic modulator and an arbitrary electrical waveform generator. Amplification at gain saturation achieves tailoring of the signal pulses. Numerical simulations with Miró software are presented and compared with experimental measurements.
ABSTRACT
We theoretically analyze the real-time formation of holographic grating driven by laser-photochemical deposition in liquid solutions. Considering the one-photon excitation of a two-level system, we present a reaction/diffusion description of the species produced photochemically by the excitation of a continuous laser wave. By assuming that a deposit is heterogeneously nucleated on the substrate when concentration of the reaction product reaches solubility, we develop a thermodynamic analysis of its late-stage growth under laser irradiation. A rate equation is proposed and used to describe the kinetics of three different types of patterning: dot array, periodic line writing, and holographic grating formed by two interfering beams. In each case, the predicted deposit growth laws show the emergence of scaling regimes that give rise to a universal picture of the processes involved, whatever the initial photosensitive medium is. Due to the crucial role played by patterned coatings in numerous practical applications (lithography or holography, for instance), this control in situ of the kinetics offers the opportunity to totally monitor the desired patterning. It also suggests the way to develop a unified description for holographic grating formation driven by photochemical deposition.
ABSTRACT
We experimentally analyze the real-time formation of periodic surface patterning resulting from laser-driven photochemical deposition in liquid solutions. Using photochemical deposition of chromium hydroxide layers driven by a continuous Ar+ laser wave in a potassium chromate solution, we analyze the kinetic formation of three different types of patterning: dot array, periodic line writing, and holographic grating formed by interfering beams. Results are also presented for both flat and curved substrates. In each case, the deposit growth laws are measured and they show the emergence of scaling regimes that are predicted by our model [Phys. Rev. E 69, 051605 (2004)]]. Data taken from literature are also confronted to the model. The observed agreement suggests that a unified picture of the processes involved for photodeposition driven by a one-photon absorption can be devised, whatever the initial photosensitive medium is. This kinetic control of photodeposition, associated to the versatility in monitoring the geometry of laser/medium interaction and the flexibility in deposited materials by various photochemical reactions, offers a valuable level of development in substrate patterning for lithographic or holographic applications.
