E.M. Dianov

Bio: E.M. Dianov is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Dispersion (optics) & Optical fiber. The author has an hindex of 10, co-authored 15 publications receiving 610 citations.

Soliton pulse compression in dispersion-decreasing fiber

Abstract: We investigate the adiabatic compression of picosecond and subpicosecond soliton pulses from all-fiber, passively mode-locked, erbium-doped fiber soliton lasers operating at 1550 nm in dispersion-decreasing fibers (DDF's). High-quality soliton compression from 630 down to 115 fs in a 100-m DDF and from 3.5 down to 230 fs in a 1.6-km DDF is obtained. The effects of third-order dispersion and Raman self-scattering on the compression process are observed and discussed.

Electrostriction mechanism of soliton interaction in optical fibers.

Abstract: In contrast to the mechanism of interaction determined by the Kerr nolinearity, the electrostrictive interaction between picosecond pulses in optical fibers can occur when the temporal interval between them is much greater than their duration. The width of the interval is determined by the lifetime of the sound wave in the fiber core region, i.e., ~1 nsec. It follows from our calculations that for long propagation distances (L > 1000 km) the relative temporal separation of the interacting pulses can reach hundreds of picoseconds at the temporal interval between them of ~1 nsec.

Picosecond soliton pulse compressor based on dispersion decreasing fibre

Abstract: The Letter reports the adiabatic compression of 2–4 ps pulses from a passively mode-locked all-fibre soliton ring laser operating at 1557 nm down to 230 fs in a 1.6 km dispersion decreasing fibre.

114 Gbit/s soliton train generation through Raman self‐scattering of a dual frequency beat signal in dispersion decreasing optical fiber

Abstract: We report the generation of 114 Gbit/s trains of 250 fs fundamental solitons. The pulses are generated due to the conversion of an intense optical beat signal (generated from two DFB laser diodes and an erbium doped fiber amplifier combination) into a soliton train due to nonlinear propagation in a 1.6 km fiber of steadily decreasing dispersion. The train repetition rate corresponds to the beat frequency of the input signal and was readily tunable between 80 and 120 GHz. The results of a computer simulation of the system are found to be in good qualitative agreement with the experimental observations.

70 Gbit/s fibre based source of fundamental solitons at 1550 nm

Abstract: We report the generation of a 70 Gbit/s CW soliton train with a mark-space ratio of 1:11 from a fibre system based on the nonlinear propagation of a dual-frequency beat-signal within dispersion decreasing fibre.

Supercontinuum generation in photonic crystal fiber

Abstract: A topical review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime. Results from numerical simulations are used to discuss the temporal and spectral characteristics of the supercontinuum, and to interpret the physics of the underlying spectral broadening processes. Particular attention is given to the case of supercontinuum generation seeded by femtosecond pulses in the anomalous group velocity dispersion regime of photonic crystal fiber, where the processes of soliton fission, stimulated Raman scattering, and dispersive wave generation are reviewed in detail. The corresponding intensity and phase stability properties of the supercontinuum spectra generated under different conditions are also discussed.

High power fiber lasers: current status and future perspectives [Invited]

Abstract: The rise in output power from rare-earth-doped fiber sources over the past decade, via the use of cladding-pumped fiber architectures, has been dramatic, leading to a range of fiber-based devices with outstanding performance in terms of output power, beam quality, overall efficiency, and flexibility with regard to operating wavelength and radiation format. This success in the high-power arena is largely due to the fiber’s geometry, which provides considerable resilience to the effects of heat generation in the core, and facilitates efficient conversion from relatively low-brightness diode pump radiation to high-brightness laser output. In this paper we review the current state of the art in terms of continuous-wave and pulsed performance of ytterbium-doped fiber lasers, the current fiber gain medium of choice, and by far the most developed in terms of high-power performance. We then review the current status and challenges of extending the technology to other rare-earth dopants and associated wavelengths of operation. Throughout we identify the key factors currently limiting fiber laser performance in different operating regimes—in particular thermal management, optical nonlinearity, and damage. Finally, we speculate as to the likely developments in pump laser technology, fiber design and fabrication, architectural approaches, and functionality that lie ahead in the coming decade and the implications they have on fiber laser performance and industrial/scientific adoption.

77-fs pulse generation from a stretched-pulse mode-locked all-fiber ring laser

Abstract: By incorporating a section of large positive-dispersion fiber in an all-fiber erbium ring laser, we obtain high-energy pulses with spectral widths of 56 nm. The chirp on these pulses is highly linear and can be compensated for with dispersion in the output coupling fiber lead. The result is a fully self-starting source of 77-fs pulse with 90 pJ of energy and greater than 1 kW of peak power at a 45-MHz repetition rate.

Stimulated Brillouin scattering in optical fibers

Abstract: We present a detailed overview of stimulated Brillouin scattering (SBS) in single-mode optical fibers. The review is divided into two parts. In the first part, we discuss the fundamentals of SBS. A particular emphasis is given to analytical calculation of the backreflected power and SBS threshold (SBST) in optical fibers with various index profiles. For this, we consider acousto-optic interaction in the guiding geometry and derive the modal overlap integral, which describes the dependence of the Brillouin gain on the refractive index profile of the optical fiber. We analyze Stokes backreflected power initiated by thermal phonons, compare values of the SBST calculated from different approximations, and discuss the SBST dependence on the fiber length. We also review an analytical approach to calculate the gain of Brillouin fiber amplifiers (BFAs) in the regime of pump depletion. In the high-gain regime, fiber loss is a nonnegligible effect and needs to be accounted for along with the pump depletion. We provide an accurate analytic expression for the BFA gain and show results of experimental validation. Finally, we review methods to suppress SBS including index-controlled acoustic guiding or segmented fiber links. The second part of the review deals with recent advances in fiber-optic applications where SBS is a relevant effect. In particular, we discuss the impact of SBS on the radio-over-fiber technology, enhancement of the SBS efficiency in Raman-pumped fibers, slow light due to SBS and SBS-based optical delay lines, Brillouin fiber-optic sensors, and SBS mitigation in high-power fiber lasers, as well as SBS in multimode and microstructured fibers. A detailed derivation of evolutional equations in the guided wave geometry as well as key physical relations are given in appendices.

Models of blocking probability in all-optical networks with and without wavelength changers

Abstract: We introduce a traffic model for circuit switched all-optical networks (AONs) which we then use to calculate the blocking probability along a path for networks with and without wavelength changers. We investigate the effects of path length, switch size, and interference length (the expected number of hops shared by two sessions which share at least one hop) on blocking probability and the ability of wavelength changers to improve performance. Our model correctly predicts unobvious qualitative behavior demonstrated in simulations by other authors.