Shih Hung Chen

TL;DR: In this article, the authors classified and characterized oscillations of various origins with detailed theoretical modeling and showed that the interplay between the absolute/convective instabilities, circuit losses, and reflective feedback leads to the concept of ultra high gain scheme which employs distributed wall losses for the suppression of spurious oscillations.

TL;DR: In this article, the authors analyzed the physical origins of spurious oscillations in gyrotron traveling wave amplifiers and provided zero-drive stability at ultra-high gain with a proof-of-principle experiment in the $\mathrm{Ka}$ band.

TL;DR: Absolute instabilities in the gyrotron traveling wave amplifier are investigated with a simulation approach which models electron and wave dynamics in the sever and distributed-loss section.

TL;DR: A Ka-band gyrotron backward-wave oscillator (gyro-BWO) experiment has been performed to investigate the phase control, fast tunability, and power capability, showing favorable scaling to still higher powers.

TL;DR: In this article, a broadband parasitic amplification in a diode-seeded nanosecond ytterbium-doped fiber laser amplifier system is numerically and experimentally investigated.