Donor–acceptor molecular design and chemical vapor deposition growth enable the two‐dimensional nickel‐tetraaminobenzoquinone films with strong broadband absorption and efficient charge separation. The resulting photodetectors exhibit a structured broadband response with a high responsivity of ∼3.1 A W−1 and a response time of ∼170 µs, which surpasses ...
Yunxu Chen +14 more
wiley +1 more source
Chiral Phonon–Driven Ultrafast Spin Currents in a Non‐Magnetic Ferroelectric
Broadband terahertz emission spectroscopy shows signatures of ultrafast spin‐current generation in non‐magnetic ferroelectric β$\beta$’‐In2Se3${\rm In}_2{\rm Se}_3$. Reversal of the emitted field upon sample inversion and substitution of Pt with W indicates spin‐Hall‐mediated charge conversion, while polarization‐resolved measurements reveal ...
Thomas B. Gill +16 more
wiley +1 more source
Wood‐Derived Nanocellulose‐Biocarbon Fresnel‐Zone Plate Lenses for Sub‐THz Frequency Applications
Wood‐derived nanocellulose and lignin‐based biocarbon were combined to fabricate fully bio‐based Fresnel zone plate (FZP) lenses for sub‐terahertz frequencies. These sustainable FZP lenses exhibit low dielectric loss and high directivity, achieving performance comparable to that of metallic references, and remain functional under environmental stress ...
Riikka Haataja +9 more
wiley +1 more source
Broadband Terahertz Spectroscopy of Phonon-Polariton Dispersion in Ferroelectrics
Electromagnetic waves at frequencies below the X-ray region strongly couple to the optical vibrational modes in a solid. These coupled excitations have been called phonon polaritons.
Seiji Kojima
doaj +1 more source
Unlocking Terahertz Steganography: Authentication of Hidden Images in Flexible Media
Hidden information in multilayered devices, such as steganographic portraits, is detected and authenticated using reflection‐mode terahertz time‐domain imaging. Image reconstruction relies on a dedicated figure‐of‐merit obtained by integrating the signal intensity over the time‐window associated with the reflection from the metallic mirror backing the ...
Tiziana Ritacco +4 more
wiley +1 more source
Inverse Optical Contrast in Metastable GeTe2: An Anomaly Enabling Low‐Loss Phase Change Photonics
An anomalous optical phase inversion in GeTe2$\mathrm{GeTe_{2}}$ provides a new platform for low‐loss non‐volatile integrated photonics at 1550 nm. The transition from the amorphous state (1) to a metastable vdW−GeTe2$\mathrm{vdW-GeTe_{2}}$ crystalline phase (2) is driven by bandgap widening, resulting in a negative refractive index change (Δn$\Delta ...
Jan Prikryl, Jan Mistrik, Milos Krbal
wiley +1 more source
A compact, continuous-wave terahertz source based on a quantum-cascade laser and a miniature cryocooler [PDF]
We report on the development of a compact, easy-to-use terahertz radiation source, which combines a quantum cascade laser (QCL) operating at 3.1 THz with a compact, low input-power Stirling cooler.
Semenov, Alexey +10 more
core +1 more source
Retina‐Inspired Bi‐Based Terahertz Photonic Neuromorphic Devices
Combined with effective band alignment and substrate engineering, bismuth materials are introduced to form terahertz photonic bio‐inspired devices with picosecond short‐term plasticity to enable multi‐scene visual perception. Thus obtained hardware through the terahertz optical neural network (THz‐ONN) demonstrates high recognition accuracy, providing ...
Pujing Zhang +14 more
wiley +1 more source
Power scaling of ultra-thin terahertz beam-splitters
Extent: 2p.A low-cost ultra-thin broadband terahertz beam-splitter based on a thin conductive layer has previously been fabricated and tested. Here, this paper shows the linearity of power scaling of the beam-splitter from lower to higher power in ...
Ng, B. +11 more
core +1 more source
Field-resolved high-order sub-cycle nonlinearities in a terahertz semiconductor laser
Two-dimensional terahertz strong-field spectroscopy reveals wave-mixing processes up to eighth order in a free-running quantum cascade laser, unraveling its sub-cycle gain dynamics and nonlinearities in a regime of negative absorption.
J. Riepl +13 more
doaj +1 more source

