All-fiber all-normal dispersion laser with a fiber-based Lyot filter

Cataloged from PDF version of article.We propose the use of a short section of polarization-maintaining fiber as a birefringent medium to construct an all-fiber Lyot filter inside the cavity of a fiber laser. This allows mode-locked operation of an all-fiber all-normal dispersion Yb-fiber oscillator without the use of a bulk bandpass filter and using standard components. Moreover, filter bandwidth and modulation depth is easily controlled by changing the length and splice angle of the polarization-maintaining-fiber section, leading to an adjustable filter. At mode-locked operation, the 30% output fiber port delivers 1 nJ pulses that are dechirped to 230 fs duration

Fiber amplification of pulse bursts up to 20 mu J pulse energy at 1 kHz repetition rate

Cataloged from PDF version of article.We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier. Groups of pulses with a temporal spacing of 10 ns and 1 kHz overall repetition rate are amplified to an average pulse energy of similar to 20 mu J and total burst energy of 0.25 mJ. The pulses are externally compressed to similar to 400 fs. The amplifier is synchronously pulsed-pumped to minimize amplified spontaneous emission between the bursts. We characterize the influence of pump pulse duration, pump-to-signal delay, and signal burst length. (C) 2011 Optical Society of Americ

All-fiber-integrated soliton-similariton laser with in-line fiber filter

Cataloged from PDF version of article.We demonstrate an all-fiber-integrated Er-doped fiber laser operating in the soliton–similariton mode-locking regime. In the similariton part of the cavity, a self-similarly evolving parabolic pulse with highly linear chirp propagates in the presence of normal dispersion. Following an in-line fiber-based birefringent filter, the pulse evolves into a soliton in the part of the cavity with anomalous dispersion. The similariton and the soliton pulses are dechirped to 75.5 and 167.2 fs, respectively, outside of the cavity. Mode-locked operation is very robust, owing to the influence of the two similariton and soliton attractors that predominate each half of the laser cavity. The experimental results are supported with numerical simulations, which provide good agreement

Diffraction-limited, 10-W, 5-ns, 100-kHz, all fiber laser at 1.55 um

Cataloged from PDF version of article.This Letter reports on an all-fiber-integrated master-oscillator, power amplifier system at 1.55 mu m producing 5-ns, 100-mu J pulses. These pulses are generated at a 100 kHz repetition rate, corresponding to 10 W of average power. The seed source is a low-power, current-modulated, single-frequency, distributed feedback semiconductor laser. System output is obtained from a standard single-mode fiber (Corning SMF-28). Consequently, the beam is truly diffraction limited, which was independently proven by M-2 measurements. Further increase of peak power is limited by onset of significant spectral broadening due to nonlinear effects, primarily four-wave mixing. Numerical simulations based on six-level rate equations with full position-and time-dependence were developed to model propagation of pulses through the amplifier chain. This capability allows minimization of the amplified spontaneous emission, which can be directly measured using a fast acousto-optic modulator to gate the pulses. (C) 2014 Optical Society of Americ

All-fiber low-noise high-power femtosecond Yb-fiber amplifier system seeded by an all normal dispersion fiber oscillator

Cataloged from PDF version of article.We report an all-fiber, high-power, low-noise ampli-fier system seeded by an all-normal-dispersion-mode-locked Ybdoped fiber laser oscillator. Up to 10.6 W of average power is obtained at a repetition rate of 43 MHz with diffraction-limited beam quality. Amplified pulses are dechirped to sub-160-fs duration in a grating compressor. It is to our knowledge the first high-power source of femtosecond pulses with completely fiber-integrated amplification comprising commercially available components. Longterm stability is excellent. Short-term stability is characterized and an integrated laser intensity noise of <0.2% is reported. We also conclude that all-normal dispersion fiber oscillators are low-noise sources, suitable as seed for fiber amplifiers. Detailed numerical modeling of both pulse generation in the oscillator and propagation in the amplifier provide very good agreement with the experiments and allow us to identify its limitations

Controlling Fast Chaos in Delay Dynamical Systems

We introduce a novel approach for controlling fast chaos in time-delay dynamical systems and use it to control a chaotic photonic device with a characteristic time scale of ~12 ns. Our approach is a prescription for how to implement existing chaos control algorithms in a way that exploits the system's inherent time-delay and allows control even in the presence of substantial control-loop latency (the finite time it takes signals to propagate through the components in the controller). This research paves the way for applications exploiting fast control of chaos, such as chaos-based communication schemes and stabilizing the behavior of ultrafast lasers.Comment: 4 pages, 4 figures, to be published in Physical Review Letter

Generation of picosecond pulses directly from a 100 W, burst-mode, doping-managed Yb-doped fiber amplifier

Cataloged from PDF version of article.Burst-mode laser systems offer increased effectiveness in material processing while requiring lower individual pulse energies. Fiber amplifiers operating in this regime generate low powers in the order of 1 W. We present a Yb-doped fiber amplifier, utilizing doping management, that scales the average power up to 100 W. The laser system produces bursts at 1 MHz, where each burst comprises 10 pulses with 10 mu J energy per pulse and is separated in time by 10 ns. The high-burst repetition rate allows substantial simplification of the setup over previous demonstrations of burst-mode operation in fiber lasers. The total energy in each burst is 100 mu J and the average power achieved within the burst is 1 kW. The pulse evolution in the final stage of amplification is initiated as self-similar amplification, which is quickly altered as the pulse spectrum exceeds the gain bandwidth. By prechirping the pulses launched into the amplifier, 17 ps long pulses are generated without using external pulse compression. The peak power of the pulses is similar to 0.6 MW. (C) 2014 Optical Society of Americ

Ansatz from Non-Linear Optics Applied to Trapped Bose-Einstein Condensates

A simple analytical ansatz, which has been used to describe the intensity profile of the similariton laser (a laser with self-similar propagation of ultrashort pulses), is used as a variational wave function to solve the Gross-Pitaevskii equation for a wide range of interaction parameters. The variational form interpolates between the noninteracting density profile and the strongly interacting Thomas-Fermi profile smoothly. The simple form of the ansatz is modified for both cylindrically symmetric and completely anisotropic harmonic traps. The resulting ground-state density profile and energy are in very good agreement with both the analytical solutions in the limiting cases of interaction and the numerical solutions in the intermediate regime.Comment: 4 pages, 3 figures, published versio