Related papers: Transient THz conductivity of silicon with optical…
We present femtosecond transient transmission (or absorbance) measurements in silicon nanowires in the energy range 1.1-3.5 eV, from below the indirect band-gap to above the direct band-gap. Our pump-probe measurements allow us to give a…
The results of high-field terahertz transmission experiments on n-doped silicon (carrier concentration of $8.7\times10^{16}$ cm$^{-3}$) are presented. We use terahertz pulses with electric field strengths up to 3.1 MV cm$^{-1}$ and a pulse…
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…
Optical pump-terahertz probe spectroscopy has been used to investigate ultrafast photo-induced charge carrier transport in 3.4 $\mu$m wide graphene ribbons upon scaling the optical pump intensity. For low pump fluences, the deposited pump…
We experimentally show that indirect light-induced electron transitions could lead to THz detection on standard CCD and CMOS sensors, introducing this well-established technological concept to the THz range. Unlike its optical counterpart,…
We measure the transmission of THz pulses through thin films of YBCO at temperatures between 10K and 300K. The pulses possess a useable bandwidth extending from 0.1 -- 1.5 THz (3.3 cm^-1 -- 50 cm^-1). Below T_c we observe pulse reshaping…
We demonstrate here an efficient THz source with low electrical power consumption. We have increased the maximum THz radiation power emitted from SI-GaAs based photoconductive emitters by two orders of magnitude. By irradiating the SI-GaAs…
The optical properties of silicon can be greatly tuned by applying strain and opening new perspectives, particularly in applications where infrared is key. In this work, we use a recent model for the indirect light absorption of silicon and…
Picosecond carrier dynamics in indium antimonide (InSb) following excitation by below-bandgap broadband far infrared radiation were investigated at 200 K and 80 K. Using a novel THz-pump/THz-probe scheme with pump THz fields of 100 kV/cm…
The degradation of signal in silicon sensors is studied under conditions expected at the CERN High-Luminosity LHC. 200 $\mu$m thick n-type silicon sensors are irradiated with protons of different energies to fluences of up to $3 \cdot…
Using an empirical pseudopotential description of electron states and an adiabatic bond charge model for phonon states in bulk silicon, we theoretically investigate two-photon indirect optical injection of carriers and spins and two-color…
Photons do not carry sufficient momentum to induce indirect optical transitions in semiconducting materials such as silicon, necessitating the assistance of lattice phonons to conserve momentum. Compared to direct bandgap semiconductors,…
We present polarization-resolved transient transmission measurements on multi-layer black phosphorus. Background free two-color pump-probe spectroscopy measurements are carried out on mechanically exfoliated black phosphorus flakes that…
Ultrafast light-matter interaction has emerged as a powerful tool to control and probe the macroscopic properties of functional materials, especially two-dimensional transition metal dichalcogenides which can form different structural…
We present measurements of the transient photoconductivity in pentacene single crystals using optical-pump THz-probe spectroscopy. We have measured the temperature and fluence dependence of the mobility of the photoexcited charge carriers…
X-ray-induced carrier dynamics in silicon and gallium arsenide were investigated through intensity variations of transmitted terahertz (THz) pulses in the pico to microsecond time scale with X-ray free-electron laser and synchrotron…
Intense few cycle terahertz pulses exhibit complex non-linear behavior under interaction with heavily n-doped Si. Fast increase in the transmission of a 700 fs pulse (central frequency 1.5 THz) through the Si sample (low field transmission…
Transient reflectivity spectroscopy is widely used to study ultrafast carrier- and phonon-dynamics in semiconductors. In their heterostructures, it is often not straightforward to distinguish contributions to the signal from the various…
Strong-field mid-infrared pump--terahertz (THz) probe spectroscopy has been proven as a powerful tool for light control of different orders in strongly correlated materials. We report the construction of an ultrafast broadband infrared…
THz Time-Resolved Photoconductivity is used to probe carrier dynamics in the dilute III-V nitride GaP0.49As0.47N0.036. In these measurements a femtosecond optical pump-pulse excites electron-hole pairs, and a delayed THz pulse measures the…