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The Maxwell-Bloch equations (MBE) describe the interaction between a two-level quantum mechanical system and an electromagnetic wave. They are widely used in nonlinear optics in general and to model quantum cascade lasers (QCLs) in particular [1]. Due to their nonlinearity, numerical methods are usually required to solve the equations. In order to cope with the computational complexity that arises,...
Bessel beams exploit conical energy flow to yield near-uniform intensity along a line focus which has been shown to be extremely attractive for laser processing in dielectrics. At high power, however, the nonlinear Kerr effect is known to induce significant oscillations of the on-axis intensity which is deleterious for machining applications. Here, we show through theory and numerical modelling how...
Optical frequency combs in space bear the prospect of dramatically improving satellite navigation and they may pave the pathway for various space applications like satellite formation flights, global satellite navigation, earth observation, and satellite-based fundamental tests of physical constants [1]. Here we report on a precision ranging system based on a dual-comb architecture aiming for fast...
It is commonly understood that, to cast light into a state with sub-Poissonian statistics, a strong optical nonlinearity is needed. The most common examples are resonance fluorescence of a two-level system, or a Kerr medium where the Kerr energy per photon U is much larger than the optical linewidth κ. In both cases, a single-photon nonlinearity is realized, whereby the presence of a single photon...
We report the new method for the measurement of the phase-relaxation time T2 of a medium with femtosecond time resolution. The method is based on the effect of quantum interference of entangled photons and does not require the actual use of a femtosecond light source. The method provides the practical and cost-efficient alternative to existing methods of ultrafast time-resolved spectroscopy [1].
Optical linear circuit is one of the most important parts for optical quantum computing. The optical circuit, which consists of mode mixers and phase shifters, has been used in various quantum protocols: cluster state generation, Boson sampling, and quantum random walk. To realize a large-scale linear circuit, waveguide-based quantum circuits have experimentally been demonstrated by some groups [1,...
In aperiodically poled quasi-phase-matching (QPM) crystals, parametric down-conversion (PDC) can generate very broadband pulsed squeezed light. This is because each part of the crystal will generate squeezed light at a different frequency [1]. But the emission will be thus inhomogeneously broadened, and one requires special measures to eliminate the chirp accompanying the pulses. This can be done...
The remarkably-high intrinsic optical nonlinearity of graphene can be pushed even further when the optical frequency is tuned to plasmon resonances hosted by the material when it is doped [1-4]. Atomistic simulations provide an accurate description of these phenomena, although their computational cost is prohibitive for large graphene nanostructures [3, 4]. An alternative formalism consists in relying...
Hybridized nanostructures composed by metals and dielectrics, semiconductors or organics offer new opportunities achieving new functionalities in nonlinear optics, plasmonics, sensing [1-4]. In particular GaAs-AlGaAs-GaAs core-shell-supershell nanowires (NWs) fabricated by self-catalyzed growth on Si substrates were partially covered with gold, thus producing a symmetry breaking in the sample geometry...
Optical rectification of ultrashort laser pulses in electro-optic crystals is an established technique of terahertz generation. In this technique, the pump optical pulse produces a nonlinear polarization that moves with the group velocity of the optical pulse and acts as a source of terahertz radiation. The up-to-date generation schemes based on this principle utilize both the standard collinear phase...
Novel nonlinear optical crystals have attracted considerable interests due to their wide applications in frequency shifting, terahertz generation, optical communications, display, sensing, and so on. Because terahertz radiation is sensitive to free carriers and lattice vibrations in solid states, terahertz time-domain spectroscopy (THz-TDS) has become a pivotal tool in investigating fundamental dynamics...
The nonlinear light-matter interaction lies at the heart of controlling the electronic systems for the purpose of developing ultrafast optical switching and modulation devices [1], and attosecond laser technology [2]. In general, the interaction causes the formation of photon dressed state that is a quantum superposition state with energetically spaced sidebands and enables to generate the phase-locked...
Two-dimensional transition metal dichalcogenide (MX2) are receiving lot of attention in recent years due to their excellent electronic and optical properties which make them feasible for advanced photonics applications [1]. In particular Molybdenum-Disulfide (MoS2) has shown large exciton binding energy, strong spin-orbit interaction, and high carrier mobilities.
The need for microoptical elements in various emerging fields such as astrophotonics, nonlinear optics and biomedicine create a demand for a new generation optics that would be lightweight/compact, resilient to harsh environment and easily integrable in other devices. Ultrafast pulses based direct laser writing 3D nanolithography produced microlenses seem as one of the candidates for such applications...
Nanowaveguides (NWs) are valuable components for building miniaturized optical devices since they have both nanoscale and microscale dimensions. One can further extend the NW application range by exploiting nonlinear optical effects such as second-harmonic (SH) and sum-frequency (SF) generation. Lithium niobate (LiNbO3) NWs and nanopillars are demonstrated to generate and guide SH [1-4] and SF [5]...
The main limitation of second-order nonlinear optical materials is the requirement of non-centrosymmetry within the electric-dipole approximation. However, higher multipole effects (such as magnetic-dipole and electric-quadrupole) do not suffer from such restriction. Thus, multipole effects can provide an interesting path towards novel second-order materials. Although multipole effects have been already...
Shock waves have been thoroughly investigated during the last century in many different branches of physics. In conservative (Hamiltonian) systems the shock singularity is regularized by weak wave dispersion, thus leading to the formation of a rapidly and regular oscillating structure, usually termed in the literature dispersive shock wave (DSW), see e.g. [1]. Here, we show that this fundamental singular...
Nonlinear wavelength generations by using the optical waveguides are more compact, low cost, and efficient than using the traditional solid state systems [1], and the generated broadband light sources can be utilized in optical coherence tomography, frequency metrology, optical communications, and many other. In this work, the high quality of tantalum pentoxide (Ta2O5) micro-ring resonator has been...
Strong interaction between two single photons [1], is a long standing and important goal in quantum photonics. This would enable a new regime of nonlinear optics and unlock several applications in quantum information science, including photon-photon gates and deterministic Bell-state measurements for quantum networking. In the context of quantum networks [2], a particularly important case is to achieve...
A current challenge and trend in optical sciences is to extend the toolbox generated from experiments with single emitters and single photons towards interfacing photons with a well-defined number of quantum emitters. The resulting complex optical network would enable studies of many-body quantum optical phenomena and could lend itself to quantum simulations. However, common light-matter interfaces...
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