Power loss in open cavity diodes and a modified Child-Langmuir law

Quantum extension of Child-Langmuir law.

Ultrashort-pulse child-langmuir law in the quantum and relativistic regimes.

This Letter presents a consistent quantum and relativistic model of short-pulse Child-Langmuir (CL) law, of which the pulse length tau is less than the electron transit time in a gap of spacing D and voltage V. The classical value of the short-pulse CL law is enhanced by a large factor due to quantum effects when the pulse length and the size of the beam are, respectively, in femtosecond durati...

Beyond the Child-Langmuir limit.

This article presents a new formulation of the solution for fully nonlinear and unsteady planar flow of an electron beam in a diode. Using characteristic variables (i.e., variables that follow particle paths) the solution is expressed through an exact analytic, but implicit, formula for any choice of incoming velocity v(0), electric field E(0), and current J(0). For steady solutions, this appro...

Application of the Modified Log-Wake Law in Open-Channels

The modified log-wake law, which was developed for turbulent boundary layers and pipe flows, is extended to turbulent flows in open-channels. Turbulent velocity profiles in open-channels can be approximated with three components: (1) the law of the wall that results from the constant bed shear stress; (2) the law of the wake that reflects the effects of gravity, secondary currents and bed rough...

Wavelength switching in multi-cavity laser diodes

We study experimentally and numerically electrical and optical methods to switch the lasing wavelength in a linear multi-cavity laser. The electrical method uses radio frequency modulation of the gain region to modify effective optical loss at a well-defined wavelength. The optical method uses injection of lasing light to modify effective photon lifetime at the injection wave-length. Short tran...