Accession Number : ADP007857

Title :   Optical Line Shapes of Quantum Wells and Quantum Wires,

Corporate Author : HITACHI LTD TOKYO (JAPAN) CENTRAL RESEARCH LAB

Personal Author(s) : Ohtoshi, T. ; Yamanishi, M.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : Optical line shapes, which represent homogeneous broadenings due to carrier collisions, play a crucial role in estimating the linear and nonlinear susceptibilities of low-dimensional semiconductors. So far, the Lorentzian function has been widely used to analyze the gain and the refractive index in quantum-well (QW) and quantum-wire lasers. However, these papers have not proven that it is truly possible to approximate the line shapes with the Lorentzian function. In this paper, the authors theoretically derive the line shape functions of QW and quantum-wire structures based on a theory involving the non-Markovian relaxation processes. The understanding of the line shapes at high-carrier densities is vital for predicting semiconductor laser properties. It is also important for estimating the line shape functions at low-carrier densities. This is because line broadening must be minimized in order to lower the switching power of ultra-fast optical devices that utilize the virtual charge-induced optical nonlinearity (VCON) effect and the ac-Stark effect under low real-excited carrier density conditions.

Descriptors :   *NONLINEAR OPTICS, COLLISIONS, DENSITY, FUNCTIONS, GAIN, INDEXES, LASERS, POWER, REFRACTIVE INDEX, RELAXATION, SEMICONDUCTOR LASERS, SHAPE, STARK EFFECT, STRUCTURES, THEORY, JAPAN, COLLISION BROADENING, OPTICAL SWITCHING.

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE