Related papers: A lasing mechanism based on absorption boundary of…
Because surface plasmons can be confined below the diffraction limit, metallic lasers that support plasmonic modes can provide miniaturized sources of electromagnetic waves. Such devices often exploit a multilayer design, in which a…
Random lasers are highly configurable light sources that are promising for imaging and photonic integration. In this study, random lasing action was generated by optically pumping MBBA liquid crystals infiltrated with gold nanoparticles and…
Understanding the behaviour of complex laser systems is an outstanding challenge, especially in the presence of nonlinear interactions between modes. Hidden features, such as the gain distributions and spatial localisation of lasing modes,…
The Raman effect -- inelastic scattering of light by lattice vibrations (phonons) -- produces an optical response closely tied to a material's crystal structure. Here we show that resonant optical excitation of IR and Raman phonons gives…
While conventional lasers are based on gain media with three or four real levels, unconventional lasers including virtual levels and two-photon processes offer new opportunities. We study lasing that involves a two-photon process through a…
Coherent perfect absorption (CPA), also known as time-reversed laser, is a wave phenomenon resulting from the reciprocity of destructive interference of transmitted and reflected waves. In this work we consider quasi one-dimensional lattice…
We perform high resolution spectroscopy of $N_2^+$ emission in light filaments using a controlled pump at 795 followed by a second harmonic weak probe. Our result suggests that transient gain is achieved by resonant stimulated Raman…
We introduce a class of unidirectional lasing modes associated with the frozen mode regime of non-reciprocal slow-wave structures. Such asymmetric modes can only exist in cavities with broken time-reversal and space inversion symmetries.…
The accumulation of atoms in the lowest energy level of a trap and the subsequent out-coupling of these atoms is a realization of a matter-wave analog of a conventional optical laser. Optical random lasers require materials that provide…
The lasing threshold of a random laser is computed numerically from a generic model. It is shown that spatial correlations of the disorder in the medium (i.e., dielectric constant) lead to an increase of the decay rates of the eigenmodes…
Reabsorption, the multiple scattering of spontaneously emitted photons in optically thick gases, is a major limitation to efficient optical pumping and laser cooling in ultracold gases. We report mitigation of reabsorption using spatial and…
A novel lasing scheme for terahertz quantum cascade lasers, based on consecutive phonon-photon-phonon emissions per module, is proposed and experimentally demonstrated. The charge transport of the proposed structure is modeled using a rate…
A theory of resonant Raman scattering spectroscopy of one dimensional electronic systems is developed on the assumptions that (i) the excitations of the one dimensional electronic system are described by the Luttinger Liquid model, (ii)…
${}^{133}\mathrm{Ba}^+$ is illuminated by a laser that is far-detuned from optical transitions, and the resulting spontaneous Raman scattering rate is measured. The observed scattering rate is lower than previous theoretical estimates. The…
We present a microscopic laser model for many atoms coupled to a single cavity mode, including the light forces resulting from atom-field momentum exchange. Within a semiclassical description, we solve the equations for atomic motion and…
The collective interaction via the environmental vacuum is investigated for a mixture of two deviating multi-atom ensembles in a moderately intense laser field. Due to the numerous inter-atomic couplings, the laser-dressed system may react…
The paper offers a discrete thermodynamic model of lasers. Laser is an open system; its equilibrium is based on a balance of two thermodynamic forces, one related to the incoming pumping power and another to the emitted light. The basic…
A fraction of a laser beam array, whose unknown phase relationships must be set to prescribed values, is launched into a scattering media with random transmission. The resulting output speckle pattern is sampled by an array of photodiodes…
We report on the creation of new lasing modes with spatially nonuniform distributions of optical gain in a one-dimensional random structure. It is demonstrated numerically that even without gain saturation and mode competition, the spatial…
We use a simple setup based on an infinite planar slab gain medium with no mirrors to explore the possibility of realizing a recently discovered resonance effect related to the mathematical concept of spectral singularity. In particular we…