arXiv subjects

V. Develay

Publications and source records attributed to V. Develay.

4 recordsLinked to original sources

arXiv2026

Mode-locking instability and multiple soliton formation in GaN polariton waveguide cavities

We study the emergence of multi-soliton regimes in 1D ridge polariton waveguides of two different lengths. We show that by varying the position of the gain, which in out-of-equilibrium polariton systems is provided by the pumping laser and its associated excitonic reservoir, it is possible to tune the regime of soliton formation between single and multiple solitons. This soliton dynamics can be quantitatively reproduced by solving the Gross-Pitaevskii equations of the coupled exciton-photon system, which show that the soliton splitting mechanism is governed by the exciton reservoir dynamics.

cond-mat.mes-hall↗

arXiv2025

Soliton formation in a bound state in the continuum GaN waveguide polariton laser

We study polaritonic bound states in the continuum (BIC) created in GaN waveguides. The existence of symmetry-protected BICs is confirmed by the suppression of light emission and the observation of a polarization vortex in momentum space. Upon increasing the pumping, polariton population accumulates at the BIC and we observe polariton lasing from the blueshifted BIC states. The assessment of the polariton BIC emission energy and of its real and momentum space wavefunctions as a function of pumping power, i.e. of polariton density, indicates the formation of a bright soliton above the lasing threshold. Soliton formation at the BIC is induced by the combination of negative mass BIC and of repulsive polariton-polariton and polariton-reservoir interactions.

cond-mat.mes-hall↗

arXiv2024

Mode-locked GaN waveguide polariton laser

So far, exciton-polariton (polariton) lasers were mostly single mode lasers based on microcavities. Despite the large repulsive polariton-polariton interaction, pulsed mode-locked polariton laser was never reported. Here, we use a $60 \ μm-$long GaN-based waveguide surrounded by distributed Bragg reflectors forming a multi-mode horizontal cavity. We demonstrate experimentally and theoretically a polariton mode-locked micro-laser operating in the blue-UV, at room temperature, with a 300$\ GHz$ repetition rate and 100$\ fs$-long pulses. The mode locking is demonstrated by the compensation (linearization) of the mode dispersion by the self-phase modulation induced by the polariton-polariton interaction. It is also supported by the observation in experiment and theory of the typical envelope frequency profile of a bright soliton.

physics.optics↗

arXiv2024

Soliton formation in an exciton-polariton condensate at a bound state in the continuum

Bound states in the continuum (BIC) are of special interest in photonics due to their theoretically infinite radiative lifetime. Here, we design a structure composed of a GaN layer with guided exciton-polaritons and a TiO$_2$ 1D photonic crystal slab. The photonic BIC hosted by the photonic crystal slab couples with the excitons of GaN to form a polaritonic BIC with a negative mass. This allows condensation to be reached with a low threshold in a structure suitable for electrical injection, paving the way for room-temperature polariton microdevices. We study in detail how the repulsive interaction between exciton-polaritons affects the condensate distribution in reciprocal space and, consequently, the condensate's overlap with the BIC resonance and, therefore, the condensate lifetime. We study an intrinsic contribution related to the formation of a bright soliton and the extrinsic contribution related to the interaction with an excitonic reservoir induced by spatially focused non-resonant pumping. We then study the peculiar dynamics of the condensation process in a BIC state for interacting particles using Boltzmann equations and hybrid Boltzmann-Gross Pitaevskii equations. We find optimal conditions allowing one to benefit from the long lifetime of the BIC for polariton condensation in a real structure.

physics.optics↗