Related papers: Tunable near- to mid-infrared pump terahertz probe…

Pumping n-type GaAs and InSb with ultrafast THz pulses having intensities higher than 150 MW/cm2 shows strong free carrier absorption saturation at temperatures of 300 K and 200 K respectively. If the energy imparted to the carriers exceeds…

The intense terahertz (THz) pulses facilitate the observation of various nonlinear optical effects and manipulation of material properties. In this work, we report a convenient approach that can produce strong broadband terahertz pulses…

Ultrafast optical excitation with intense mid-infrared and terahertz pulses has emerged as a new tool to control materials dynamically. As most experiments are performed with femtosecond pulse excitation, typical lifetimes of most…

We report here an experimental setup to perform three-pulse pump-probe measurements over a wide wavelength and temperature range. By combining two pump pulses in the visible (650-900 nm) and mid-IR (5-20 $\mu$m) range, with a broadband…

We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at…

We present a terahertz time-domain spectroscopy (THz-TDS) system which accesses a broadband spectrum, efficiently covering the so-called "new THz gap" between 5 and 15 THz and extending beyond 25 THz. The system exploits nonlinear…

We have extended the range of the high-pressure optical spectroscopy to the far-infrared region keeping the accuracy of ambient-pressure experiments. The newly-developed method offers a powerful tool for the study of pressure-induced phase…

Terahertz (THz) waves have been significantly developed in the last fifteen years because of their great potential for applications in industrial and scientific communities1,2. The unique properties of THz waves as transparency for numerous…

In an ultrafast optical-pump terahertz-probe measurement, the photoinduced material response can be modulated on a timescale shorter than the extent of the THz pulse. In this situation, the measured time-frequency response deviates from a…

Linear terahertz time-domain spectroscopy (THz-TDS) is a sensitive probe for material characterization including thickness measurements of thin layers. These applications critically rely on a sufficiently large bandwidth, which is not…

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…

A whole class of two-color experiments involves intense, short Terahertz radiation pulses. A fast detector that is sensitive and able to resolve both near-infrared and Terahertz pulses at the same time is highly desirable. Here we present…

Room temperature Terahertz stimulated emission and population inversion in optically pumped graphene is reported. We experimentally observe fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in an…

Electrical control of amplitude and phase of terahertz radiation (THz) is the key technological challenge for high resolution and noninvasive THz imaging. The lack of an active materials and devices hinders the realization of these imaging…

High-power multi-color terahertz (THz) radiation exhibits extraordinary scientific application prospects at various scientific frontiers, for its capacity to deliver THz excitation at multiple frequencies simultaneously. However, the…

Near-field imaging with terahertz (THz) waves is emerging as a powerful technique for fundamental research in photonics and across physical and life sciences. Spatial resolution beyond the diffraction limit can be achieved by collecting THz…

We discuss terahertz pump-probe experiments in hBN from the perspective of Floquet optical materials and photonic time crystals. Anisotropic nature of this material results in a large separation of frequencies of in-plane and out-of-plane…

A tilted-pulse-front pumped terahertz pulse source is proposed for the generation of extremely high field single-cycle terahertz pulses. The very simple and compact source consists of a single crystal slab having a blazed reflection grating…

We report a newly designed mid-infrared-pump visible-probe measurement system, which can measure phase-sensitive responses to a mid-infrared pulse along the oscillating electromagnetic field. In this system, the pump light is a phase-locked…

Imaging applications in the terahertz (THz) frequency range are severely restricted by diffraction. Near-field scanning probe microscopy is commonly employed to enable mapping of the THz electromagnetic fields with sub-wavelength spatial…