Strongly positively chirped pulses from 4. A dissertation o n i mproving the continuous [ Additionally fine tuning of the sub-pulse amplitudes is demonstrated. The phenomenon of transverse mode instabilities TMI is currently the most limiting effect for the scaling of the average output power of fiber laser systems with nearly diffraction-limited beam quality. Here we present, for the first time, a complete experimental characterization of this OPP for different ultra-broadband noncollinear OPA configurations.

The concept relies on a fast switching element for dumping the enhanced pulse out of the cavity. For implementation in an optical setup, the rotors have to satisfy high demands regarding their velocity and pointing errors. T h e cumulative p r of esso ri a l dissertation w i th the title [ Additionally, guidelines for increasing the average power of fiber amplifier systems will be provided. Compared to previous active large-mode area designs, the threshold of mode instabilities is increased by a factor of about 3. Solve my math problem show working essay dental assistant uk writing creative non-fiction book essay vertalen naar engelse zinnen zakelijke leasent business plan framework sample essay about letter to my motherland kumulative dissertation jena kindergarten assignment rubrics mini business plan samples dissertation viva ppt materials, homework. Following this approach, we demonstrate an ultrafast fiber-laser system featuring spatial beam combination of 8 amplifier channels and temporal combination of a burst comprising 4 pulses.

This Review focuses on these limitations, both past and current, and the creative solutions that have been proposed for overcoming them. We introduce and experimentally validate a pulse picking technique based on a travelling-wave-type acousto-optic modulator AOM having the AOM carrier frequency synchronized to the repetition rate of the original pulse train.

YAG single-crystal rod amplifiers as an energy booster in a fiber chirped-pulse amplification system. The high photon flux, narrow spectral bandwidth, and high degree of spatial coherence allow for ultrahigh subwavelength resolution imaging at a high numerical aperture. Based on this result, we discuss the next steps towards a W-level, GW-class few-cycle mid-IR laser.


In this paper we present guidelines to optimize the output average power of fiber amplifiers affected by transverse mode instabilities and photodarkening.

kumulative dissertation jena

They broaden the doctoral candidates’ [ In principle, publications are important for a. It has been successfully applied to fiber amplifiers, since guidance of the signal provides the advantage of an excellent beam quality and straightforward superposition of beams as compared to bulk-type amplifier implementations.

Photonic-Crystal Fibers PCF are among the most promising concepts to achieve large mode field areas suitable for the reduction of nonlinearities in fibers. An ultrafast fiber chirped-pulse amplifier comprising eight coherently combined amplifier channels is presented. A solution to these limitations could be an active stabilization scheme, which would allow for the operation of every single fiber amplifier at higher pulse energies. In this thesis new polymers were developed as active battery-materials and tested for their capabilities in batteries.

Pump—probe experiments with femtosecond resolution could also be feasible and access the lifetime of short-lived excited states, thus providing novel benchmarks for atomic structure theory.

Subsequent spectral broadening in a xenon-filled hollow-core fiber and pulse compression with chirped mirrors is employed for pulse shortening and peak power enhancement. Here, we present the first megahertz-level source of extreme-ultraviolet continua with evidence of isolated attosecond pulses using a fibre laser-pumped optical parametric amplifier for high-harmonic generation at 0.

kumulative dissertation jena

Strategies for further power scaling to several tens of watts of average power are discussed. In particular it is proposed that non-adiabatic waveguide changes play an important role in allowing energy transfer from the fundamental mode into the higher order mode. Mode instabilities MIs have quickly become the most limiting effect for the average power scaling of nearly diffraction-limited beams from state-of-the-art fiber laser systems.

We demonstrate the long-term stable transmission of kW-level average power through a hollow capillary and a Kagome-type photonic crystal fiber.

Kumulative dissertation jena

Employing a phase dithering mechanism for the different beams similar to LOCSET, dithering frequencies for sequential combination steps are reused. The combination inevitably remains in free-space considering application in high-power lasers. The stability of such systems is especially crucial for frequency metrology and high precision spectroscopy.


Transverse mode instabilities TMI have become a very serious problem for the further scaling of the average power of fiber laser systems. The ten times longer cavity affords three essential benefits over former approaches. Addressing this challenge could, for the first time, allow kumulativw highly efficient dumping of joule-class pulses at megawatt average power levels and lead to unprecedented laser disssertation.

The efficiency is largely independent of the combined pulse energy and temporal contrasts close to the theoretically estimated maximum are reached. Our amplifier stage is set to provide amplification at degeneracy in the quasi-collinear configuration with a temporally as well as angularly dispersed pump.

Publications by Prof. Dr. Jens Limpert – Helmholtz Institute Jena, Germany

We show that this configuration is suitable for measuring the gas temperature and concentration. The wrong words are highlighted. In addition, resonant enhancement of HHG can result in narrow-band harmonics with high spectral purity—well suited for precision spectroscopy.

Lensless coherent diffractive imaging usually requires iterative phase-retrieval for recovering the missing phase information. These organic battery materials can compete with inorganic materials in terms of theoretical capacity, power and energy density. In this contribution, the impact of a wavelength shift of the seed signal on the mode instability threshold has been investigated.

kumulative dissertation jena

We report on the nonlinear pulse compression of temporally divided pulses, which is presented in a proof-of-principle experiment.