Related papers: Terahertz generation by beamlet superposition
This is a brief overview of the main physical ideas for application of field effect transistors for generation and detection of TeraHertz radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the…
We generate spatially multimode twin beams using 4-wave mixing in a hot atomic vapor in a phase-insensitive traveling-wave amplifier configuration. The far-field coherence area measured at 3.5 MHz is shown to be much smaller than the…
We consider a periodically gated two-dimensional electron system, with a central gate finger biased independently creating a tunable plasmonic cavity in a planar plasmonic crystal. We demonstrate that the plasmons resonantly excited in the…
Graphene as a zero-bandgap two-dimensional semiconductor with a linear electron band dispersion near the Dirac points has the potential to exhibit very interesting nonlinear optical properties. In particular, third harmonic generation of…
We are reporting on terahertz generation from organic crystal BNA using a 1.15 to 1.55 um near infrared pump. We observed a very large emission spectrum extending up to 7 THz, compared to 2.5 THz from Ti:Sa pump in previous reports. The…
Magneto-terahertz phenomena are the main focus of the thesis. This work started as supporting research for the science of an X-ray laser (SwissFEL). X-ray lasers have recently drawn great attention as an unprecedented tool for scientific…
We present a universal and rigorous approach to study difference frequency generation in the terahertz domain, keeping the number of degrees of freedom to a minimum, through the definition of a suitable figure of merit. The proposed method…
A novel method is presented for generating radiation using the beat wave associated with a bi-frequency laser pulse, to excite plasma oscillations in a plasma slab with a density gradient. By resonantly exciting a plasma wave, it can be…
We present the generation of THz radiation by focusing ultrafast laser pulses with three incommensurate wavelengths to form a plasma. The three colors include 800 nm and the variable IR signal and idler outputs from an optical parametric…
The efficient generation of terahertz (THz) waves in two-dimensional (2D) MXene layers driven by near-infrared femtosecond laser pulses is demonstrated through predictive simulations. Employing a novel hydrodynamic model that…
Semiconductor superlattices are strongly nonlinear media offering several technological challenges associated with the generation of high-frequency Gigahertz radiation and very effective frequency multiplication up to several Terahertz.…
We demonstrate a Terahertz photomixer pumped by mid-infrared photons at 10$\mu$m wavelength. The device is based on a dual-antenna architecture, in which a two-dimensional array of mid-infrared patch-antenna resonators is connected to the…
We report on the observation of terahertz radiation in a non-centrosymmetric insulating oxide, paratellurite ($\alpha$-TeO$_2$) by irradiation of a femtosecond laser pulse at room temperature. In the power spectrum of the terahertz…
Adoption of terahertz technologies is hindered by the lack of cost-effective THz sources. Here we demonstrate a fundamentally new way to generate and control THz radiation, via spatio-temporal emissivity modulation. By patterning the…
Terahertz nonlinear optics is a viable method to interrogate collective phenomena in quantum materials spanning ferroelectrics, charge-density waves, and superconductivity. In superconductors this includes the Higgs amplitude and Josephson…
Supercontinuum generation by femtosecond filaments in air is investigated for different laser wavelengths ranging from ultraviolet to infrared. Particular attention is paid on the role of third-harmonic generation and temporal steepening…
Recent studies in spintronics have highlighted ultrathin magnetic metallic multilayers as a novel and very promising class of broadband terahertz radiation sources. Such spintronic multilayers consist of ferromagnetic (FM) and non-magnetic…
Organic crystals offer promising potential for THz generation, but face limitations in wavelength tunability and damage threshold. By applying tilted pulse front pumping to organic crystals an additional degree of freedom is introduced into…
Terahertz lies at the juncture between RF and optical electromagnetism, serving as a transition from mm-Wave to infrared photonics. Terahertz technology has been used for industrial quality control, security imaging, and high-speed…
An analytical formulation of a radially polarized laser pulse propagating in a homogeneous, magnetized plasma is presented using Lorentz force, continuity and Maxwells equations. Perturbation technique and quasi-static approximation (QSA)…