Accession Number : ADA336389

Title :   Ultralow Threshold Microlasers.

Descriptive Note : Final rept. 01 Jul 96-31 Oct 97,

Corporate Author : UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES

Personal Author(s) : Levi, A. F. ; Dapkus, P. D.

PDF Url : ADA336389

Report Date : OCT 1997

Pagination or Media Count : 20

Abstract : This final technical report summarizes advances to push the limits of ultralow threshold microlaser VCSEL design implementation, and performance. The main results are summarized: (1) Values of spontaneous emission coupling factor B(beta) in the range between 10(exp -2) and 10(exp -1) lead to comparatively low turn-on delay for both on-on and on-off modulation. Spontaneous emission factors lying between 10(exp -2) and 10(exp -1) are more attractive than devices with B approx. 1. (2) With reduction of aperture size to less than 5x5 sq micrometers. the internal quantum efficiency decreases owing to carrier losses resulting from current spreading and carrier out-diffusion, the round-trip loss increases due to excess diffraction and scattering losses. (3) Modal noise and speckle visibility in Gb/s multimode waveguide interconnect systems depends on a complex interplay of carrier dynamics, spontaneous emission factor, gain compression, and device dimensions. Scaled low-power microlasers exhibit modal noise comparable to large incoherent multimode devices. (4) The series resistance of microlasers has been explored by fabricating low resistance, low-threshold current, and intracavity-contacted devices.

Descriptors :   *THRESHOLD EFFECTS, *LASERS, COMPRESSION, LOW POWER, EMISSION, SCATTERING, DYNAMICS, RESISTANCE, WAVEGUIDES, REDUCTION, INCOHERENCE, DIFFRACTION, INTERNAL, VISIBILITY, GAIN, DELAY, QUANTUM EFFICIENCY, MULTIMODE, LOSSES, NOISE, MODULATION, APERTURES, MINIATURE ELECTRONIC EQUIPMENT.

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE