arXiv subjects

Alexey Ermolov

Publications and source records attributed to Alexey Ermolov.

4 recordsLinked to original sources

arXiv2019

CEP-stable soliton-based pulse compression to 4.4 fs and UV generation at 800 kHz repetition rate

We report generation of a femtosecond supercontinuum extending from the ultraviolet to the near-infrared and detection of its carrier-envelope phase variation by f-to-2f interferometry. The spectrum is generated in a gas-filled hollow-core photonic crystal fiber where soliton dynamics allows CEP-stable self-compression of OPCPA pump pulses at 800 nm to a duration of 1.7 optical cycles, followed by dispersive wave emission. The source provides up to 1 μJ of pulse energy at 800 kHz repetition rate resulting in 0.8 W of average power, and can be extremely useful for example in strong-field physics, pump-probe measurements and ultraviolet frequency comb metrology.

physics.optics↗

arXiv2018

UV soliton dynamics and Raman-enhanced supercontinuum generation in photonic crystal fiber

Ultrafast broadband ultraviolet radiation is of importance in spectroscopy and photochemistry, since high photon energies enable single-photon excitations and ultrashort pulses allow time-resolved studies. Here we report the use of gas-filled hollow-core photonic crystal fibers (HC-PCFs) for efficient ultrafast nonlinear optics in the ultraviolet. Soliton self-compression of 400 nm pulses of (unprecedentedly low) ~500 nJ energies down to sub-6-fs durations is achieved, as well as resonant emission of tunable dispersive waves from these solitons. In addition, we discuss the generation of a flat supercontinuum extending from the deep ultraviolet to the visible in a hydrogen-filled HC-PCF. Comparisons with argon-filled fibers show that the enhanced Raman gain at high frequencies makes the hydrogen system more efficient. As HC-PCF technology develops, we expect these fiber-based ultraviolet sources to lead to new applications.

physics.optics↗

arXiv2017

Soliton-effect self-compressed single-cycle 9.6-W mid-IR pulses from a 21-W OPCPA at 3.25 μm and 160 kHz

We report a 21-W mid-IR OPCPA that generates 131-μJ and 97 fs (sub-9-cycle) pulses at 160 kHz repetition rate and at a centre wavelength of 3.25 μm. Pulse-to-pulse stability of the CEP-stable output is excellent with 0.33% rms over 288 million pulses (30 min) and compression close to a single optical cycle was achieved through soliton self- compression inside a gas-filled mid-IR anti-resonant-guiding photonic crystal fibre. Without any additional compression device, stable generation of 14.5 fs (1.35-optical-cycle) pulses was achieved at an average power of 9.6 W. The resulting peak power of 3.9 GW in combination with the near-single-cycle duration and intrinsic CEP stability, make our OPCPA a key-enabling technology for the next generation of extreme photonics, strong-field attosecond research and coherent X-ray science.

physics.optics↗

arXiv2015

Supercontinuum generation in the vacuum ultraviolet through dispersive-wave and soliton-plasma interaction in noble-gas-filled hollow-core photonic crystal fiber

We report on the generation of a three-octave-wide supercontinuum extending from the vacuum ultraviolet (VUV) to the near-infrared, spanning at least 113 to 1000 nm (i.e., 11 to 1.2 eV), in He-filled hollow-core kagome-style photonic crystal fiber. Numerical simulations confirm that the main mechanism is a novel and previously undiscovered interaction between dispersive-wave emission and plasma-induced blueshifted soliton recompression around the fiber zero dispersion frequency. The VUV part of the supercontinuum, which modeling shows to be coherent and possess a simple phase structure, has sufficient bandwidth to support single-cycle pulses of 500 attosecond duration. We also demonstrate, in the same system, the generation of narrower-band VUV pulses, through dispersive-wave emission, tunable from 120 to 200 nm with efficiencies exceeding 1% and VUV pulse energies in excess of 50 nJ.

physics.optics↗