Related papers: Rectified diode response of a multimode quantum ca…
Single-mode semiconductor lasers subject to optical injection have been shown to trigger a wide range of dynamical behavior from injection locking to chaos. Multi-wavelength lasers add even more degrees of freedom and complexity to the…
We analyze the peculiar case where the free carrier absorption arising from LO phonon absorption-assisted transitions becomes negative and therefore turns into a gain source for quantum cascade lasers. Such an additional source of gain…
We present the first report of the synchronization regimes in both unidirectionally and bidirectionally-coupled multiple time delay chaotic laser diodes subject to incoherent optical feedbacks and incoherent optical injection. We derive the…
We have investigated the photoexcited transient responses of stripe-ordered phase in a cuprate superconductor, ${\rm La}_{1.6-x}{\rm Nd}_{0.4}{\rm Sr}_{x}{\rm CuO}_{4}~(x = 0.12)$ using optical-pump terahertz (THz)-probe spectroscopy. Upon…
Mode-locking operation and multimode instabilities in Terahertz (THz) quantum cascade lasers (QCLs) have been intensively investigated during the last decade. These studies have unveiled a rich phenomenology, owing to the unique properties…
We investigate the transient response of a $\Lambda$-type system with one transition decaying to a modified radiation reservoir with an inverse square-root singular density of modes at threshold, under conditions of transparency. We…
A quantum cascade laser where the quantum wells in the active regions are replaced by quantum dots with their atom-like discrete energy levels is an interesting system to study novel features in optical spectroscopy. We study structures…
The transparence of a laser-driven optical resonator containing an ensemble of cold atoms can have two distinct, robust states. Atoms in their initially prepared pure state blockade the transmission by detuning the cavity mode from the…
The induced terahertz response of semiconductor systems is investigated with a microscopic theory. In agreement with recent terahertz experiments, the developed theory fully explains the ultrafast build up of the plasmon resonance and the…
The transverse mode of an atom laser beam that is outcoupled from a Bose-Einstein condensate is investigated and is found to be strongly determined by the mean--field interaction of the laser beam with the condensate. Since for repulsive…
A thermal diode transports heat mainly in one preferential direction rather than in the opposite direction. This behavior is generally due to the non-linear dependence of certain physical properties with respect to the temperature. Here we…
Ring lasers exhibit rich operational regimes such as unidirectional, bidirectional, or bistable operation. The two-mode dynamics of the counter-propagating modes - clockwise (CW) and counterclockwise (CCW) and their selection, have gained…
A phase modulated RF current source is applied to an injection locked diode laser operating at $780\unit{nm}$. This produces tunable phase modulated sidebands of the laser suitable for stabilizing the length of an optical transfer cavity…
We experimentally and theoretically study the response of a superradiant or bad-cavity laser to an applied coherent drive. We observe two forms of synchronization (injection locking) between the superradiant ensemble and the applied drive:…
We present a simple and effective method to implement an active stabilization of a diode laser with injection locking, which requires minimal user intervenes. The injection locked state of the diode laser is probed by a photodetector, of…
THz quantum cascade lasers based on a novel buried cavity geometry are demonstrated by combining double-metal waveguides with proton implantation. Devices are realised with emission at 2.8 THz, displaying ultra low threshold currents of 19…
We report on the first direct measurement of the emission character of quantum cascade laser based frequency combs, using intensity autocorrelation. The correlation technique is based on fast electro-optic sampling, with a bandwidth…
Terahertz quantum cascade laser sources based on intra-cavity difference frequency generation from mid-IR devices are an important asset for applications in rotational molecular spectroscopy and sensing, beingthe only electrically pumped…
Simultaneous strong coherent pumping of the two transitions of a V-level atom with very differentdecay rates has been predicted to create almost perfect inversion on the narrower transition. Usingthe example of the blue and red transitions…
Quantum cascade laser (QCL)-pumped molecular lasers (QPMLs) have recently been introduced as a new source of powerful (>1 mW), tunable (>1 THz), narrow-band (<10 kHz), continuous-wave terahertz radiation. The performance of these lasers…