60 research outputs found
Quantum revival for elastic waves in thin plate
Quantum revival is described as the time-periodic reconstruction of a wave
packet initially localized in space and time. This effect is expected in
finite-size systems which exhibits commensurable discrete spectrum such as the
infinite quantum well. Here, we report on the experimental observation of full
and fractional quantum revival for classical waves in a two dimensional cavity.
We consider flexural waves propagating in thin plates, as their quadratic
dispersion at low frequencies mimics the dispersion relation of quantum systems
governed by Schr\"{o}dinger equation. Time-dependent excitation and measurement
are performed at ultrasonic frequencies and reveal a periodic reconstruction of
the initial elastic wave packet.Comment: submitted to the special issue of EPJ ST in honor of scientific
legacy of Roger Maynar
Linear and Non-linear Rabi Oscillations of a Two-Level System Resonantly Coupled to an Anderson-Localized Mode
We use time-domain numerical simulations of a two-dimensional (2D) scattering
system to study the interaction of a collection of emitters resonantly coupled
to an Anderson-localized mode. For a small electric field intensity, we observe
the strong coupling between the emitters and the mode, which is characterized
by linear Rabi oscillations. Remarkably, a larger intensity induces non-linear
interaction between the emitters and the mode, referred to as the dynamical
Stark effect, resulting in non-linear Rabi oscillations. The transition between
both regimes is observed and an analytical model is proposed which accurately
describes our numerical observations.Comment: 11 pages, 6 figure
Localized Modes in a Finite-Size Open Disordered Microwave Cavity
We present measurements of the spatial intensity distribution of localized
modes in a two-dimensional open microwave cavity randomly filled with
cylindrical dielectric scatterers. We show that each of these modes displays a
range of localization lengths and successfully relate the largest value to the
measured leakage rate at the boundary. These results constitute unambiguous
signatures of the existence of strongly localized electromagnetic modes in
two-dimensionnal open random media
2D tunable all-solid-state random laser in the visible
A two-dimensional (2D) solid-state random laser emitting in the visible is
demonstrated, in which optical feedback is provided by a controlled disordered
arrangement of air-holes in a dye-doped polymer film. We find an optimal
scatterer density for which threshold is minimum and scattering is the
strongest. We show that the laser emission can be red-shifted by either
decreasing scatterer density or increasing pump area. We show that spatial
coherence is easily controlled by varying pump area. Such a 2D random laser
provides with a compact on-chip tunable laser source and a unique platform to
explore non-Hermitian photonics in the visibleComment: 5 pages, 4 figure
Broadband, Single wavelength, Continuous Spectral Control in a Polymer-Based Solid-State Random Laser
In this paper, we present a study on partially pumped, single wavelength
random lasing with tunability controlled by temperature in a solid-state random
laser based on DCM
(4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) doped PMMA
(polymethyl methacrylate) dye. By carefully shaping the spatial profile of the
pump, we achieve low-threshold, single-mode random lasing with excellent
rejection of side lobes. Notably, we observe that varying the temperature
induces changes in the refractive index of the PMMA-DCM layer, resulting in a
blue-shift of the lasing wavelength. Moreover, we demonstrate continuous
tunability of the lasing wavelength over an impressive bandwidth of 8 nm.Comment: 7 pages, 4 figur
Optofluidic random laser
An active disordered medium able to lase is called a random laser (RL). We
demonstrate random lasing due to inherent disorder in a dye circulated
structured microfluidic channel. We consistently observe RL modes which are
varied by changing the pumping conditions. Potential applications for on-chip
sources and sensors are discussed.Comment: 3 pages, 4 figure
Temperature-controlled spectral tuning of a single wavelength polymer-based solid-state random laser
Funding. Engineering and Physical Sciences Research Council (EPSRC[EP/V029975/1]); PICS-ALAMO; Planning and Budgeting Committee of the Council for Higher Education of Israel (2015-2018); United States-Israel Binational Science Foundation (BSF #2022158, NSF/BSF #2015694, NSF/BSF #2021811); Israel Science Foundation (1871/15,2074/15, 2630/20).We demonstrate temperature-controlled spectral tunability of a partially-pumped single-wavelength random laser in a solid-state random laser based on DCM (4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) doped PMMA (polymethyl methacrylate) dye. By carefully shaping the spatial profile of the pump, we first achieve low-threshold, single-mode random lasing with excellent side lobes rejection. Notably, we show how temperature-induced changes in the refractive index of the PMMA-DCM layer result in a blue shift of this single lasing mode. We demonstrate spectral tunability over an 8nm-wide bandwidth.Publisher PDFPeer reviewe
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