Related papers: Negative free carrier absorption in terahertz quan…
Absorption of light is directly associated with dissipative processes in a material. In suitably tailored resonators, a specific level of dissipation can support coherent perfect absorption, the time-reversed analogue of lasing, which…
The realization of high-$\beta$ lasers is one of the prime applications of cavity-QED promising ultra-low thresholds, integrability and reduced power consumption in the field of \textit{green photonics}. In such nanolasers spontaneous…
Intersubband transitions in a superlattice under homogeneous electric field is studied within the tight-binding approximation. Since the levels are equi-populated, the non-zero response appears beyond the Born approximation. Calculations…
Quantum cascade laser frequency combs are nowadays well-appreciated sources for infrared spectroscopy. Here their applicability for free-space optical communication is demonstrated. The spontaneously-generated intermodal beat note of the…
Interpretation of experiments on quantum dot (QD) lasers presents a challenge: the phonon bottleneck, which should strongly suppress relaxation and dephasing of the discrete energy states, often seems to be inoperative. We suggest and…
The equations for the effective medium refractive index and for the confinement factor in the waveguide design for quantum cascade lasers are derived.Compared to equations used in prior literature, by applying rigorous perturbation theory…
We investigate the feasible limits for realising a continuously evaporated atom laser with high-temperature sources. A plausible scheme for realising a truly continuous atom laser is to outcouple atoms from a partially condensed Bose gas,…
We analyze theoretically a superlattice structure proposed by A. Andronov et al. [JETP Lett 102, 207 (2015)] to give Terahertz gain for an operation point with positive differential conductivity. Here we confirm the existence of gain and…
The standard quantum limit to the linewidth of a laser for which the gain medium can be adiabatically eliminated is $\ell_{0}=\kappa/2\bar{n}$. Here $\kappa$ is the intensity damping rate and $\bar{n}$ the mean photon number. This contains…
We analyse the extraction of a coherent atomic beam from a trapped Bose-Einstein condensate using a rf transition to a non-trapping state at T=0 K. Our quantum treatment fully takes gravity into account but neglects all interactions in the…
Even though the terahertz spectrum is well suited for chemical identification, material characterization, biological sensing and medical imaging, practical development of these applications has been hindered by the attributes of terahertz…
Here we demonstrate a Y coupled terahertz (THz) quantum cascade laser (QCL) system. The two THz QCLs working around 2.85 THz are driven by independent electrical pulsers. Total peak THz output power of the Y system, with both arms being…
We devise a new technique to enhance transmission of quantum information through linear optical quantum information processors. The idea is based on applying the Quantum Zeno effect to the process of photon absorption. By frequently…
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…
Terahertz sources based on intra-cavity difference-frequency generation in mid-infrared quantum cascade lasers (THz DFG-QCLs) have recently emerged as the first monolithic electrically-pumped semiconductor sources capable of operating at…
In this work, we demonstrate that in a regime of strong modulation, by generating pulses of the length of the order of a few cavity lifetimes (hundreds of ps), a broadband quantum cascade laser can be driven to lase on a bandwidth (250cm-1)…
The peculiarities of electric current are studied occurring in semiconductors with strongly nonuniform distribution of charge carriers. The formation of such nonuniformities and the regulation of carrier mobilities can be realized by means…
A laser-induced acoustic desorption source, developed for use at central facilities, such as free-electron lasers, is presented. It features prolonged measurement times and a fixed interaction point. A novel sample deposition method using…
We theoretically study the conditions under which two laser fields can undergo Coherent Perfect Absorption (CPA) when shined on a single-mode bi-directional optical cavity coupled with two two- level quantum emitters (natural atoms,…
We study oscillations in quantum cascade lasers due to traveling electric field domains, which are observed both in simulations and experiments. These oscillations occur in a range of negative differential resistance and we clarify the…