arXiv subjects

Dmitry V. Skryabin

Publications and source records attributed to Dmitry V. Skryabin.

At least 19 recordsLinked to original sources

arXiv2025

Modulation instability and frequency-comb generation in hybrid quadratic-cubic resonators with spectral filtering

We present an analytical and numerical investigation into the phenomenon of filter-induced modulation instability in passive hybrid optical resonators exhibiting quadratic and cubic nonlinearity. We show that asymmetric spectral losses, with respect to the continuous-wave solution frequency, can trigger sideband amplification in the normal dispersion regime. We calculate the parametric gain and demonstrate the associated pattern formation process. We furthermore show how this parametric process can be exploited to generate optical frequency combs with tunable repetition rate.

physics.optics↗

arXiv2025

Hyperparametric solitons in nondegenerate optical parametric oscillators

Dissipative solitons and their associated low-noise, chip-scale frequency combs hold great potential for applications in optical communications, spectroscopy, precision time-keeping, and beyond. These applications drive interest in shifting soliton spectra to frequency bands far detuned from the telecom's C-band pump sources. Recent demonstrations have utilized second-harmonic generation and degenerate optical parametric oscillators (OPOs) to shift soliton combs away from the primary pump. However, these approaches lack the tunability offered by nondegenerate OPOs. This work presents a proof-of-principle demonstration of solitons in a silicon-nitride microresonator-based nondegenerate OPO system with engineered dispersion and optimized coupling rates. By pumping a relatively low-Q resonance in the C-band, we excite a signal soliton comb centred around a far-detuned, high-Q O-band resonance. This process also generates repetition-rate-locked combs at the pump and idler frequencies, with the latter occurring at a wavelength beyond 2$μ$m. We demonstrate that the solitons supported by this platform are distinct from other families of dissipative solitons and call them - hyperparametric solitons. They emerge when the narrow-band signal mode, phase-matched under negative pump detuning, reaches sufficient power to drive bistability in the parametric signal. We investigate the properties of hyperparametric solitons, including their parametrically generated background and multisoliton states, both experimentally and through theoretical modelling.

physics.optics↗

arXiv2023

Carrier-resolved real-field theory of multi-octave frequency combs

Optical frequency combs are pillars of precision spectroscopy, and their microresonator realization serves applications where miniaturization and large tooth separation are important. Microresonator combs cover an enormous range of time scales varying from the femtosecond periods of optical oscillations to milliseconds corresponding to the kilohertz linewidth of the comb teeth. Here, we develop and implement the carrier-resolved real-field model for multi-octave frequency combs, which allows for nearly ab initio capture of all the time scales involved. As an example, we consider a microresonator that has a mix of second- and third-order nonlinearities and uses periodic poling. By applying the real-field approach, we demonstrate how to surpass traditional limitations and model the spectral broadening and soliton mode-locking across three optical octaves.

physics.optics↗

arXiv2023

Two-colour dissipative solitons and breathers in microresonator second-harmonic generation

Frequency conversion of dissipative solitons associated with the generation of broadband optical frequency combs having a tooth spacing of hundreds of giga-hertz is a topical challenge holding the key to practical applications in precision spectroscopy and data processing. The work in this direction is underpinned by fundamental problems in nonlinear and quantum optics. Here, we present the dissipative two-colour bright-bright and dark-dark solitons in a quasi-phase-matched microresonator pumped for the second-harmonic generation in the near-infrared spectral range. We also found the breather states associated with the pulse front motion and collisions. The soliton regime is found to be typical in slightly phase-mismatched resonators, while the phase-matched ones reveal broader but incoherent spectra and higher-order harmonic generation. Soliton and breather effects reported here exist for the negative tilt of the resonance line, which is possible only via the dominant contribution of second-order nonlinearity.

physics.optics↗

arXiv2022

Polariton lasing in AlGaN microring with GaN/AlGaN quantum wells

Microcavity polaritons are strongly interacting hybrid light-matter quasiparticles, which are promising for the development of novel light sources and active photonic devices. Here, we report polariton lasing in the UV spectral range in microring resonators based on GaN/AlGaN slab waveguides, with experiments carried out from 4 K up to room temperature. Stimulated polariton relaxation into multiple ring resonator modes is observed, which exhibit threshold-like dependence of the emission intensity with pulse energy. The strong exciton-photon coupling regime is confirmed by the significant reduction of the free spectral range with energy and the blueshift of the exciton-like modes with increasing pulse energy. Importantly, the exciton emission shows no broadening with power, further confirming that lasing is observed at electron-hole densities well below the Mott transition. Overall, our work paves the way towards development of novel UV devices based on the high-speed slab waveguide polariton geometry operating up to room temperature with potential to be integrated into complex photonic circuits.

physics.optics↗

arXiv2022

Mid-infrared frequency combs and staggered spectral patterns in $χ^{(2)}$ microresonators

The potential of frequency comb spectroscopy has aroused great interest in generating mid-infrared frequency combs in the integrated photonic setting. However, despite remarkable progress in microresonators and quantum cascade lasers, the availability of suitable mid-IR comb sources remains scarce. Here, we present a new approach for the generation of mid-IR microcombs through cascaded three-wave-mixing. By pumping a CdSiP$_2$ microresonator at 1.55 $μ$m wavelength with a low power continuous wave laser, we generate $χ^{(2)}$ frequency combs at 3.1 $μ$m wavelength, with a span of about 30 nm. We observe ordinary combs states with a line spacing of the free spectral range of the resonator, and combs where the sideband numbers around the pump and half-harmonic alternate, forming staggered patterns of spectral lines. Our scheme for mid-IR microcomb generation is compatible with integrated telecom lasers. Therefore, it has the potential to be used as a simple and fully integrated mid-IR comb source, relying on only one single material.

physics.optics↗

arXiv2021

Solitons near avoided mode crossing in $χ^{(2)}$ nanowaveguides

We present a model for $χ^{(2)}$ waveguides accounting for three modes, two of which make an avoided crossing at the second harmonic wavelength. We introduce two linearly coupled pure modes and adjust the coupling to replicate the waveguide dispersion near the avoided crossing. Analysis of the nonlinear system reveals continuous wave (CW) solutions across much of the parameter-space and prevalence of its modulational instability. We also predict the existence of the avoided-crossing solitons, and study peculiarities of their dynamics and spectral properties, which include formation of a pedestal in the pulse tails and associated pronounced spectral peaks. Mapping these solitons onto the linear dispersion diagrams, we make connections between their existence and CW existence and stability. We also simulate the two-color soliton generation from a single frequency pump pulse to back up its formation and stability properties.

physics.optics↗

arXiv2021

Optical-parametric-oscillation-based $χ^{(2)}$ frequency comb in a lithium niobate microresonator

Microresonator frequency combs based on the $χ^{(3)}$ nonlinearity are nowadays well understood and making their way into different applications. Recently, microresonator frequency combs based on the $χ^{(2)}$ nonlinearity are receiving increasing attention, as they promise certain benefits, but still require further study. Here, we demonstrate the generation of a $χ^{(2)}$ frequency comb, initiated via optical parametric oscillation (OPO) in a lithium niobate mm-sized microresonator. By pumping at 532 nm with 30 $μ$W of power, we observe 1-THz-wide comb spectra around 1064 nm with degenerate and non-degenerate states. We also show that comb generation requires signal and idler waves to be degenerate in mode numbers and how the fulfillment of this condition can be identified from the temperature tuning curves. The results demonstrate the potential to directly generate frequency combs via OPO beyond 3 $μ$m wavelengths in the mid-IR by puming in the near-IR region.

physics.optics↗

arXiv2021

Controlling microresonator solitons with the counter-propagating pump

Considering a bidirectionally pumped ring microresonator, we provide a concise derivation of the model equations allowing us to eliminate the repetition rate terms and reduce the nonlinear interaction between the counter-propagating waves to the power-dependent shifts of the resonance frequencies. We present the simulation results of the soliton control by swiping the frequency of the counter-propagating wave in the forward and backward directions and with the soliton-blockade effect either present or not. We highlight the non-reciprocity of the forward and backward scans. Furthermore, we report the soliton crystals and breathers existing in the vicinity of the blockade interval.

physics.optics↗

arXiv2020

Soliton blockade in bidirectional microresonators

We report a method to control - disrupt and restore, a regime of the unidirectional soliton generation in a bidirectionally pumped ring microresonator. This control, i.e., the soliton blockade, is achieved by tuning pump frequency of the counterrotating field. The blockade effect is correlated with the emergence of a dark-bright nonlinear resonance of the cw-states.

physics.optics↗

arXiv2020

Spatiotemporal solitons in dispersion-managed multimode fibers

We develop the scheme of dispersion management (DM) for three-dimensional (3D) solitons in a multimode optical fiber. It is modeled by the parabolic confining potential acting in the transverse plane in combination with the cubic self-focusing. The DM map is adopted in the form of alternating segments with anomalous and normal group-velocity dispersion. Previously, temporal DM solitons were studied in detail in single-mode fibers, and some solutions for 2D spatiotemporal "light bullets", stabilized by DM, were found in the model of a planar waveguide. By means of numerical methods, we demonstrate that stability of the 3D spatiotemporal solitons is determined by the usual DM-strength parameter, $S$: they are quasi-stable at $ S S_{0}$. Stable vortex solitons are constructed too. We also consider collisions between the 3D solitons, in both axial and transverse directions. The interactions are quasi-elastic, including periodic collisions between solitons which perform shuttle motion in the transverse plane.

physics.optics↗

arXiv2020

Coupled-mode theory for microresonators with quadratic nonlinearity

We use Maxwell's equations to derive several models describing the interaction of the multi-mode fundamental field and its second harmonic in a ring microresonator with quadratic nonlinearity and quasi-phase-matching. We demonstrate how multi-mode three-wave mixing sums entering nonlinear polarisation response can be calculated via Fourier transforms of products of the field envelopes. Quasi-phase-matching gratings with arbitrary profiles are incorporated seamlessly into our models. We also introduce several levels of approximations allowing to account for dispersion of nonlinear coefficients and demonstrate how coupled-mode equations can be reduced to the envelope Lugiato-Lefever-like equations with self-steepening terms. An estimate for the $χ^{(2)}$ induced cascaded Kerr nonlinearity, in the regime of imperfect phase-matching, puts it above the intrinsic Kerr effect by several orders of magnitude.

physics.optics↗

arXiv2020

Raman solitons in waveguides with simultaneous quadratic and Kerr nonlinearities

We analyse Raman-induced self-frequency shift in two-component solitons supported by both quadratic and cubic nonlinearities. Treating Raman terms as a perturbation, we derive expressions for soliton velocity and frequency shifts of the fundamental frequency and second harmonic soliton components. We find these predictions compare well with simulations of soliton propagation. We also show that Raman shift can cause two-component solitons to approach the boundary of their own existence and subsequently trigger soliton instabilities. In some cases these instabilities are accompanied by an almost complete transfer of power to the second harmonic, and emergence of a single-component Kerr solitonic pulse.

physics.optics↗

arXiv2020

A hierarchy of coupled mode and envelope models for bi-directional microresonators with Kerr nonlinearity

We consider interaction of counter-propagating waves in a bi-directionally pumped ring microresonator with Kerr nonlinearity. We introduce a hierarchy of the mode expansions and envelope functions evolving on different time scales set by the cavity linewidth and nonlinearity, dispersion, and repetition rate, and provide a detailed derivation of the corresponding hierarchy of the coupled mode and of the Lugiato-Lefever-like equations. An effect of the washout of the repetition rate frequencies from the equations governing dynamics of the counter-propagating waves is elaborated in details.

physics.optics↗

arXiv2019

Frequency comb generation via cascaded second-order nonlinearities in microresonators

Optical frequency combs are revolutionising modern time and frequency metrology. In the past years, their range of applications has increased substantially, driven by their miniaturisation through microresonator-based solutions. The combs in such devices are typically generated using the third-order $χ^{(3)}$-nonlinearity of the resonator material. An alternative approach is making use of second-order $χ^{(2)}$-nonlinearities. While the idea of generating combs this way has been around for almost two decades, so far only few demonstrations are known, based either on bulky bow-tie cavities or on relatively low-$Q$ waveguide resonators. Here, we present the first such comb that is based on a millimetre-sized microresonator made of lithium niobate, that allows for cascaded second-order nonlinearities. This proof-of-concept device comes already with pump thresholds as small as 2 mW, generating repetition-rate-locked combs around 1064 nm and 532 nm. From the nonlinear dynamics point of view, the observed combs correspond to the Turing roll patterns.

physics.optics↗

arXiv2019

Spatiotemporal dissipative solitons and vortices in a multi-transverse-mode fiber laser

We introduce a model for spatiotemporal modelocking in multimode fiber lasers, which is based on the (3+1)-dimensional cubic-quintic complex Ginzburg-Landau equation (cGLE) with conservative and dissipative nonlinearities and a 2-dimensional transverse trapping potential. Systematic numerical analysis reveals a variety of stable nonlinear modes, including stable fundamental solitons and breathers, as well as solitary vortices with winding number $n=1$, while vortices with $n=2$ are unstable, splitting into persistently rotating bound states of two unitary vortices. A characteristic feature of the system is bistability between the fundamental and vortex spatiotemporal solitons.

physics.optics↗

arXiv2019

Finite-dimensional bistable topological insulators: From small to large

Photonic topological insulators supporting unidirectional topologically protected edge states represent attractive platform for realization of disorder- and backscattering-immune transport of edge excitations in both linear and nonlinear regimes. In many realizations of topological insulators structured periodic materials are used, since they may admit specific Dirac degeneracy in the spectrum, around which unidirectional edge states appear under the action of physical effects breaking time-reversal symmetry. While properties of the edge states at unclosed interfaces of two bulk media with different topology are known, the existence of the edge states in practical finite-dimensional topological insulators fully immersed in nontopological environment remains largely unexplored. In this work using as an example realistic polariton topological insulators built from small-size honeycomb arrays of microcavity pillars, we illustrate how topological properties of the system build up upon gradual increase of its dimensionality. To account for dissipative nature of polariton condensate forming in the array of microcavity pillars, we consider the impact of losses and resonant pump leading to rich bistability effects in this system. We describe the mechanism in accordance with which trivial-phase pump "selects" and excites specific nonlinear topological edge states circulating along the periphery of the structure in the azimuthal direction dictated by the direction of the external applied magnetic field. We also show the possibility of utilization of vortex pump with different topological charges for selective excitation of different edge currents.

physics.optics↗

arXiv2019

Floquet topological insulator laser

We introduce a class of topological lasers based on the photonic Floquet topological insulator concept. The proposed system is realized as a truncated array of the lasing helical waveguides, where the pseudo-magnetic field arises due to twisting of the waveguides along the propagation direction that breaks the time-reversal symmetry and opens up a topological gap. When sufficient gain is provided in the edge channels of the array then the system lases into the topological edge states. Topological lasing is stable only in certain intervals of the Bloch momenta, that ensure a dynamic, but stable balance between the linear amplification and nonlinear absorption leading to the formation of the breathing edge states. We also illustrate topological robustness of the edge currents by simulating lattice defects and triangular arrangements of the waveguides.

physics.optics↗