Semiconductor Microcavity Lasers Research Articles

Control of spontaneous emission in microcavity laser diodes

In this paper it is shown that a semiconductor/insulator material system is available to meet the Yablonovich criterion for the creation of a photonic band gap in periodic layered materials. The implications of using this system in the design of low threshold semiconductor lasers are considered. A suggestion is made for seeking an analogy for the mode density in practical microcavity semiconductor lasers where enhanced spontaneous emission may allow progress towards thresholdless laser operation.

Microcavity semiconductor laser with enhanced spontaneous emission.

A metal-clad optical waveguide with a semiconductor microcavity structure is proposed to increase the coupling efficiency of spontaneous emission into a lasing mode (spontaneous emission coefficient \ensuremath{\beta}) and to increase a total spontaneous emission rate simultaneously. Such a microcavity semiconductor laser with enhanced spontaneous emission has novel characteristics, including high quantum efficiency, low threshold pump rate, broad modulation bandwidth, and intensity noise reduced to below the shot-noise limit (amplitude squeezing).

Analysis of semiconductor microcavity lasers using rate equations

The rate equations for a microcavity semiconductor laser are solved and the steady-state behavior of the laser and some of its dynamic characteristics are investigated. It is shown that by manipulating the mode density and the spontaneous decay rates of the cavity modes, the threshold gain can be decreased and the modulation speed can be improved. However, in order to fully exploit the possibilities which the modification of the spontaneous decay opens up, the active material volume in the cavity must be smaller than a certain value. Threshold current using different definitions, population inversion factor, L-I curves, linewidth, and modulation response are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>