Related papers: Separation of interface and substrate carrier dyna…
Information technology demands high-speed optoelectronic devices, but going beyond the one terahertz (THz) barrier is challenging due to the difficulties associated with generating, detecting, and processing high-frequency signals. Here, we…
The detection of spatial or temporal variations in very thin samples has important applications in the biological sciences. For example, cellular membranes exhibit changes in lipid composition and order, which in turn modulate their…
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…
Selective optical excitation of a substrate lattice can drive phase changes across hetero-interfaces. This phenomenon is a non-equilibrium analogue of static strain control in heterostructures and may lead to new applications in optically…
We explore the effect of temperatures between 80 and 720 K on the energy and linewidth of zone-center transverse (TO) and longitudinal (LO) optical phonons in bulk gallium phosphide (GaP) using Fourier transform infrared ellipsometry from…
Optical second-harmonic generation is demonstrated to be a sensitive probe of the buried interface between the lattice matched semiconductors gallium phosphide and silicon with (001) orientation. Rotational anisotropy measurements of SHG…
We present a measurement of phonon propagation in a silicon wafer utilizing an array of frequency-multiplexed superconducting resonators coupled to a single transmission line. The electronic readout permits fully synchronous array sampling…
The broadband and ultrafast photoresponse of graphene has been extensively studied in recent years, although the photoexcited carrier dynamics is still far from being completely understood. Different experimental approaches imply either one…
Superconducting parametrons in the single-photon Kerr regime, also called KPOs, have been attracting increasing attention in terms of their applications to quantum annealing and universal quantum computation. It is of practical importance…
By means of a metal opto-acoustic transducer we generate quasi-longitudinal and quasi-transverse picosecond strain pulses in a (311)-GaAs substrate and monitor their propagation by picosecond acoustic interferometry. By probing at the…
Si-SiO2 multilayer nanocomposite (NCp) films, grown using pulsed laser deposition with varying Si deposition time are investigated using Raman spectroscopy/mapping for studying the variation of Si phonon frequency observed in these NCps.…
Understanding the thermal response of optical and acoustic phonons is crucial for designing functional polymer nanocomposites. We study silicon nanoparticle (Si NP)-epoxy composites using combined Raman and Brillouin spectroscopy under…
Semiconductor heterojunctions are foundational to many advanced electronic and optoelectronic devices. However, achieving high-quality, lattice-mismatched interfaces remains challenging, limiting both scalability and device performance.…
We present the intrinsic optical properties over a broad spectral range of TiN thin films deposited on a Si/SiO$_2$ substrate. We analyze the measured reflectivity spectra of the film-substrate multilayer structure within a well-establish…
Superionic conductors, or solid-state ion-conductors surpassing 0.01 S/cm in conductivity, can enable more energy dense batteries, robust artificial ion pumps, and optimized fuel cells. However, tailoring superionic conductors require…
This paper presents a study on performance optimization and resonant frequency modification of terahertz detectors by the use of hyper-hemispherical silicon superstrate lenses. The detectors are patch-TeraFETs, i.e., field-effect…
There is increased interest in the heterogeneous integration of various compound semiconductors with Si for a variety of electronic and photonic applications. This paper focuses on integrating GaAsSb (with absorption in the C-band at…
The transient response of an intrinsic graphene, which is caused by the ultrafast interband transitions, is studied theoretically for the range of pumping correspondent to the saturated absorption regime. Spectral and temporal dependencies…
Ultrafast optical pump-probe spectroscopy measurement on monolayer graphene observes significant optical nonlinearities. We show that strongly photoexcited graphene monolayers with 35 fs pulses quasi-instantaneously build up a broadband,…
We report femtosecond time-resolved reflectivity measurements of coherent phonons in tellurium performed over a wide range of temperatures (3K to 296K) and pump laser intensities. A totally symmetric A$_{1}$ coherent phonon at 3.6 THz…