Transient gain phenomena and their improvement in a fast-axial flow CO2 laser amplifier.

Self-Fields Effects on Gain in a Helical Wiggler Free Electron Laser with Ion-Channel Guiding and Axial Magnetic Field

In this paper, we have investigated the effects of self-fields on gain in a helical wiggler free electron laser with axial magnetic field and ion-channel guiding. The self-electric and self-magnetic fields of a relativistic electron beam passing through a helical wiggler are analyzed. The electron trajectories and the small signal gain are derived. Numerical investigation is shown that for grou...

Amplifier Structure for High Gain and Fast Settling Applications

High gain amplifiers with fast settling times are needed for high-speed data converter applications. A cascaded amplifier architecture is discussed that can make use of several architecturally identical amplifies to achieve the desired gain. Only one of the amplifiers has a gainbandwidth product requirement that is modestly higher than the rest to keep the overall structure stable in the presen...

Laser Anemometer Measurements in a Transonic Axial Flow Compressor Rotor

Coherent instabilities in a semiconductor laser with fast gain recovery

Christine Y. Wang, L. Diehl, A. Gordon, C. Jirauschek, F. X. Kärtner,* A. Belyanin, D. Bour, S. Corzine, G. Höfler, M. Troccoli, J. Faist, and Federico Capasso Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, USA Department of Electrical Engineering and Computer Science a...

Local improvement of flow and noise performances of axial-flow fans in a household refrigerator

In this paper, numerical and experimental investigations on an axial-flow fan with grooved/double-sectional blades are performed to improve its performance in terms of volume flow rate and noise at a local operating point. The target fan is used to cool a mechanical room of a household refrigerator. However, it is found that the target system has more resistance than that for which the fan is o...