arXiv subjects

Vladimir L. Kalashnikov

Publications and source records attributed to Vladimir L. Kalashnikov.

25 records · Page 2Linked to original sources

arXiv2010

Dissipative solitons: perturbations and chaos formation

The perturbations of chirped dissipative solitons are analyzed in the spectral domain. It is shown, that the structure of the perturbed chirped dissipative soliton is highly nontrivial and has a tendency to an enhancement of the spectral perturbations especially at the spectrum edges, where the irregularities develop. Even spectrally localized perturbations spread over a whole soliton spectrum. As a result of spectral irregularity, the chaotic dynamics develops due to the spectral loss action. In particular, the dissipative soliton can become fragmented though remains localized.

physics.optics↗

arXiv2010

Microjoule mode-locked oscillators: issues of stability and noise

In this work, for the first time to our knowledge, stability and noise of a thin-disk mode-locked Yb:YAG oscillator operating in both negative- (NDR) and positive-dispersion (PDR) regimes have been analyzed systematically within a broad range of oscillator parameters. It is found, that the scaling of output pulse energy from 7 $μ$J up to 55 $μ$J in the NDR requires a dispersion scaling from -0.013 ps$^{2}$ up to -0.31 ps$^{2}$ to provide the pulse stability. Simultaneously, the energy scaling from 6 $μ$J up to 90 $μ$J in the PDR requires a moderate dispersion scaling from 0.0023 ps$^{2}$ up to 0.011 ps$^{2}$. A chirped picosecond pulse in the PDR has a broader spectrum than that of a chirp-free soliton in the NDR. As a result, a chirped picosecond pulse can be compressed down to a few of hundreds of femtoseconds. A unique property of the PDR has been found to be an extremely reduced timing jitter. The numerical results agree with the analytical theory, when spectral properties of the PDR and the negative feedback induced by spectral filtering are taken into account.

physics.optics↗

arXiv2010

Chirped Dissipative Solitons

The analytical theory of chirped dissipative soliton solutions of nonlinear complex Ginzburg-Landau equation is exposed. Obtained approximate solutions are easily traceable within an extremely broad range of the equation parameters and allow a clear physical interpretation as a representation of the strongly chirped pulses in mode-locked both solid-state and fiber oscillators. Scaling properties of such pulses demonstrate a feasibility of sub-mJ pulse generation in the continuous-wave mode-locking regime directly from an oscillator operating at the MHz repetition rate.

physics.optics↗

arXiv2009

The unified theory of chirped-pulse oscillators

A completely analytical theory of chirped-pulse oscillators is presented. The theory is based on an approximate integration of the generalized nonlinear complex Ginzburg-Landau equation. The obtained parametric space of a chirped-pulse oscillator allows easy tracing the characteristics of both solid-state and fiber oscillators operating in the positive dispersion regime.

physics.optics↗

arXiv2008

Mode-locked oscillators in the positive and negative dispersion regimes: scenarios of destabilization

We analyze the influence of spectrally modulated dispersion and loss on the stability of mode-locked oscillators. In the negative dispersion regime, a soliton oscillator can be stabilized in a close proximity to zero-dispersion wavelength, when spectral modulation of dispersion and loss are strong and weak, respectively. If the dispersion is close to zero but positive, we observe chaotic mode-locking or a stable coexistence of the pulse with the CW signal. The results are confirmed by experiments with a Cr:YAG oscillator.

physics.optics↗

arXiv2008

Chirped-pulse oscillators: an impact of the dynamic gain saturation

An effect of the dynamic gain saturation on chirped-pulse oscillator was investigated. It was found, that the dynamic gain saturation causes strong perturbations of the pulse front that destabilizes an oscillator. As a result, the chirped-pulse exists only within some limited range of dispersions and there is a limit of energy growth for a given resonator period.

physics.optics↗

arXiv2003

Static spherically symmetric collapsar in the relativistic theory of gravitation: numerical approach and stability analysis

Numerical investigation of the static spherically symmetric vacuum solution of the Logunov equations confirms the analytical results and demonstrates a strong repulsion at sub-Planckian distance from the Schwarzschild-like singularity, which is stable against the small perturbations. We suppose that the final stage of the stellar collapse in the relativistic theory of gravitation can entail the gravitational bursts with the gravitons overproduction due to the strong deceleration in the vicinity of the Schwarzschild sphere. The rigorous investigation of this topic requires a quantum-field consideration.

astro-ph↗