Antiferromagnetic Spin Wave Amplification by Scattering in the Presence of Non-Uniform Dzyaloshinskii-Moriya Interaction.

In this study, we suggest a method to amplify spin waves (SWs) in antiferromagnets (AFMs). By introducing a non-uniform Dzyaloshinskii-Moriya (DM) interaction, the potential barrier forms a resonant cavity. SWs with an opposite chirality undergo scattering and are resonantly amplified at a phase-matching condition.

Exciton-Dominated Ultrafast Optical Response in Atomically Thin PtSe.

Strongly bound excitons are a characteristic hallmark of 2D semiconductors, enabling unique light-matter interactions and novel optical applications. Platinum diselenide (PtSe ) is an emerging 2D material with outstanding optical and electrical properties and excellent air stability. Bulk PtSe is a semimetal, but its atomically thin form shows a semiconducting phase with the appearance of a band-gap, making one expect strongly bound 2D excitons.

Medical X-band linear accelerator for high-precision radiotherapy.

Purpose: Recently, high-precision radiotherapy systems have been developed by integrating computerized tomography or magnetic resonance imaging to enhance the precision of radiotherapy. For integration with additional imaging systems in a limited space, miniaturization and weight reduction of the linear accelerator (linac) system have become important. The aim of this work is to develop a compact medical linac based on 9.

Development of a compact X-band linear accelerator system mounted on an O-arm rotating gantry for radiation therapy.

A compact X-band linear accelerator (LINAC) system equipped with a small and lightweight magnetron was constructed to develop a high-precision image-guided radiotherapy system. The developed LINAC system was installed in an O-ring gantry where cone-beam computed tomography (CBCT) was embedded. When the O-arm gantry is rotated, an x-ray beam is stably generated, which resulted from the stable transmission of radio frequency power into the X-band LINAC system.

Transmission characteristics of all-dielectric guided-mode resonance filter in the THz region.

In this study we report the first on the terahertz (THz) transmission characteristics of a guided-mode resonance (GMR) filter made of all-dielectric material. Two strong transverse electric (TE) resonance modes, TE and TE, and one strong transverse magnetic (TM) resonance mode, TM, were detected. The measured resonances can be explained by diffraction from the grating surface of the GMR filter, and by guiding along the inside of the filter (slab waveguide).

Enhanced THz guiding properties of curved two-wire lines.

We present experimental and simulation studies of enhanced terahertz (THz) guiding properties of curved two-wire lines for several surface conditions. When a THz-wave propagates through curved two-wire lines, a rough wire surface with dielectric coating contributes to a lower bending loss compared to a smooth or rough wire surface without coating. Dielectric coating and rough surface confine the THz field to the wire surface making the bending loss low.

Accelerated esterification of free fatty acid using pulsed microwaves.

It was demonstrated that pulsed microwave irradiation is a more effective method to accelerate the esterification of free fatty acid with a heterogeneous catalyst than continuous microwave irradiation. A square-pulsed microwave with a 400 Hz repetition rate and a 10-20% duty cycle with the same energy as the continuous microwave were used in this study. The pulsed microwaves improved the esterification conversion from 39.

High speed scanning of terahertz pulse by a rotary optical delay line.

We demonstrate high speed scanning of a time-domain terahertz pulse by a rotary optical delay line (RODL) incorporated into a photoconductive antenna based terahertz system. The delay line of RODL consists of six rotating convex reflective blades with a rotating speed controlled for a wide range of scan repetition rates. It can perform path length scans of 2.

Fast scanning of a pulsed terahertz signal using an oscillating optical delay line.

We describe a fast measurement of a pulsed terahertz signal generated by a femtosecond laser and a photoconductive antenna using an oscillating optical delay line. The method to measure the amplitude of the retroreflector in the oscillating optical delay line is proposed and the displacement of the retroreflector is exactly calculated to acquire the optical delay time in the fast scan mode. With the different oscillation frequency and amplitude of the retroreflector, the pulsed terahertz signals are measured and analyzed.