45 research outputs found
Experimental simulation of solid-state phenomena using photonic lattices
No full textThe propagation of light waves across a periodic array of evanescently coupled optical
waveguides can be described by a Schr¨odinger-like equation for a particle in a periodic
potential. This mapping allows us to investigate the dynamics of electrons in a
crystalline solid using an artificial crystal of optical waveguides, known as a photonic
lattice. The unique capabilities of ultrafast laser inscription enable us to design, fabricate
and precisely control various properties of a photonic lattice. Here, we focus on the
experimental construction of the Hamiltonians associated with various complex quantum
systems using engineered photonic lattices, and then measure the time evolution of
a given input state. In this photonic platform, we experimentally observe various single
particle effects known from solid-state physics, such as the localised states associated
with flat-band lattice geometries, localised Wannier-Stark states, photon-assisted tunnelling
and the anomalous topological edge modes in slowly-driven lattices. Specific
phenomena associated with particle interactions, such as the dynamics of two interacting
particles in a one-dimensional lattice with static and sinusoidally driven Hubbard
Hamiltonian, is also investigated. The experimental results presented here will be of interest
to a large community, including physicists working on photonics, quantum optics,
cold atomic gases, and condensed-matter physics
Determining the effective mode index in laser fabricated optical waveguides using Bragg gratings
No full textWe present a novel method to experimentally determine the effective index of the mode in ultrafast laser inscribed optical waveguides by characterizing a set of waveguide Bragg gratings
Observation of robust flat-band localization in driven photonic rhombic lattices
No full textWe demonstrate that a flat-band state in a quasi-one-dimensional rhombic lattice is robust in the presence of external drivings along the lattice axis. The lattice was formed by periodic arrays of evanescently coupled optical waveguides, and the external drivings were realized by modulating the paths of the waveguides. We excited a superposition of flat-band eigenmodes at the input and observed that this state does not diffract in the presence of static as well as high-frequency sinusoidal drivings. This robust localization is due to destructive interference of the analogous wavefunction and is associated with the symmetry in the lattice geometry. We then excited the dispersive bands and observed Blochoscillations and coherent destruction of tunneling respectively
Movie2_Soliton_Evolution_1T.mp4
No full textDynamics of a single-period Floquet soliton in the anomalous Floquet topological lattice shown in Fig.~2 in the main text.
Here, the driving parameter is , and the renormalized power is . The soliton reproduces itself after {\it each driving period} (up to a phase factor)
Movie1_Soliton_Evolution_2T.mp4
No full textDynamics of a period-doubled Floquet soliton in the anomalous Floquet topological lattice shown in Fig.~2 in the main text. Here, the driving parameter is , and the renormalized power is . The soliton reproduces itself after {\it two driving periods} (up to a phase factor)
Observation of localized flat-band modes in a quasi-one-dimensional photonic rhombic lattice
No full textWe experimentally demonstrate the photonic realization of a dispersionless flat band in a quasi-one-dimensional photonic lattice fabricated by ultrafast laser inscription. In the nearest neighbor tight binding approximation, the lattice supports two dispersive and one nondispersive (flat) band. We experimentally excite superpositions of flat-band eigenmodes at the input of the photonic lattice and show the diffractionless propagation of the input states due to their infinite effective mass. In the future, the use of photonic rhombic lattices, together with the successful implementation of a synthetic gauge field, will enable the observation of Aharonov-Bohm photonic caging.</p
Period-doubled Floquet Solitons
No full textWe propose and experimentally demonstrate a family of Floquet solitons in the
bulk of a photonic topological insulator that have double the period of the
drive. Our experimental system consists of a periodically-modulated honeycomb
lattice of optical waveguides fabricated by femtosecond laser writing. We
employ a Kerr nonlinearity in which self-focusing gives rise to spatial lattice
solitons. Our photonic system constitutes a powerful platform where the
interplay of time-periodic driving, topology and nonlinearity can be probed in
a highly tunable way.Comment: 5 pages, 3 figures, Supplementary Informatio
Period-doubled Floquet Solitons
No full textWe propose and experimentally demonstrate a family of Floquet solitons in the bulk of a photonic topological insulator that have double the period of the drive. Our experimental system consists of a periodically-modulated honeycomb lattice of optical waveguides fabricated by femtosecond laser writing. We employ a Kerr nonlinearity in which self-focusing gives rise to spatial lattice solitons. Our photonic system constitutes a powerful platform where the interplay of time-periodic driving, topology and nonlinearity can be probed in a highly tunable way
